JP2008266410A - Fluorescent substance, fluorescent substance-containing composition, manufacturing method of fluorescent substance, light emitting apparatus, image display device, and illuminating device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent substance for emitting a high luminance and high characteristic green fluorescence having a comparatively short emission peak wavelength and a narrow half band width. <P>SOLUTION: The fluorescent substance has a chemical composition represented by the following formula: (M<SP>I</SP><SB>(1-x)</SB>M<SP>II</SP><SB>x</SB>)<SB>α</SB>SiO<SB>β</SB>(wherein M<SP>I</SP>is two or more kinds of elements including at least Ba and Sr, selected from the group consisting of Ba, Sr, Ca, Zn and Mg. With the premise that the molar ratios of Ba and Sr with respect to total M<SP>I</SP>are [Ba] and [Sr] respectively, the value represented by [Ba]/[Sr] is in a range of 8.5≤[Ba]/[Sr]≤100. M<SP>II</SP>is one or more kinds of divalent or trivalent metal elements. Each x, α and β satisfy 0.04≤x<0.3, 1.5≤α≤2.5, and 3.5≤β≤4.5.), respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a phosphor that emits green fluorescence, a phosphor-containing composition and a light emitting device using the phosphor, a manufacturing method for manufacturing the phosphor, an image display device and an illumination using the light emitting device Relates to the device. More specifically, a green phosphor suitable for a backlight for liquid crystal, a phosphor-containing composition and a light emitting device using the green phosphor, a manufacturing method for producing the phosphor, and an image display using the light emitting device The present invention relates to a device and a lighting device.

  The white light essential for lighting and display applications is generally obtained by combining blue, green and red light emission by the principle of additive mixing of light. In backlights for color liquid crystal display devices, a field of display applications, each of the blue, green, and red light emitters has as much light intensity as possible in order to efficiently reproduce a wide range of colors on the chromaticity coordinates. Highness and good color purity are desired. For example, NTSC (National Television Standard Committee) is known as one of the standards for the color reproduction range of TV.

  Recently, an attempt has been made to use a semiconductor light emitting device as the light source of these three colors. However, it is not common to use semiconductor light emitting devices for all three colors because a circuit for compensating the color shift during use is required. Therefore, it is practical to obtain the desired three colors by converting the wavelength of light emitted from the semiconductor light emitting element using a phosphor. Specifically, blue, green, and red light are emitted using a near-ultraviolet light emitting semiconductor light emitting device as a light source, and light emitted from the blue light emitting semiconductor light emitting device is used as blue as it is. A method obtained by conversion is known.

  Of these three colors, green is particularly important compared to the other two colors because it has the highest visibility to the human eye and contributes greatly to the overall brightness of the display.

As a phosphor emitting green fluorescence (hereinafter referred to as “green phosphor” as appropriate), the center wavelength of the fluorescence is usually 498 nm or more, preferably 510 nm or more, and usually 550 nm or less, preferably 540 nm or less. Is desirable. Examples of such green phosphors include, for example, europium activated alkaline earth silicon oxynitride phosphors represented by (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu, (Ba, Ca, Sr). , Mg) ₂ SiO ₄ : Euopium activated alkaline earth magnesium silicate phosphor represented by Eu.

  However, these conventionally known green phosphors are difficult to meet demands for brightness and chromaticity and have not been put into practical use.

Patent Document 1 describes SrBaSiO ₄ : Eu as a known example of a phosphor that obtains green light emission by converting the wavelength of near ultraviolet light or blue light from a semiconductor light emitting element.

  However, the phosphor described in Patent Document 1 has a narrow color reproduction range and low luminance, and is insufficient for the above purpose.

  In addition, Patent Document 1 describes that the wavelength can be changed by changing the composition of Ba, Sr, and Ca. However, the composition and the manufacturing method described in the examples are used. All of the phosphors had low conversion efficiency with respect to blue light or near ultraviolet light, and were insufficient to satisfy both the color reproduction range and the luminance.

US Pat. No. 6,982,045

  A green light emitter for a display device such as a display is required to have an emission peak wavelength in the vicinity of 525 nm, a high luminance, and a half width as narrow as possible. However, the existing green phosphors typified by those described in Patent Document 1 are insufficient in terms of color reproduction range and luminance. For this reason, a high-quality green phosphor suitable for the above purpose has been desired.

  The present invention has been made in view of the above-mentioned problems, and an object thereof is a phosphor emitting green fluorescence, which has a relatively short emission peak wavelength, a narrow half-value width, and high luminance and high characteristics. And a phosphor-containing composition and a light emitting device using the phosphor, a manufacturing method for producing the phosphor, and an image display device and an illumination device using the light emitting device are provided. That is.

  In view of the above problems, the present inventors have studied the composition ratio of alkaline earth metal elements in detail, and as a result, a phosphor having a specific composition range is suitable as a green phosphor for a display device such as a display. I found.

That is, the gist of the present invention resides in a phosphor having a chemical composition represented by the following formula [1] (claim 1).
(M ^I _(1-x) M ^II _x ) _α SiO _β [1]
(Wherein [1], M ^I is, Ba, Sr, Ca, selected from the group consisting of Zn and Mg, represents two or more elements including at least Ba and Sr. However, Ba and for the entire M ^I If Sr molar ratio of which is respectively [Ba] and [Sr], is in the range of [Ba] / value represented by [Sr] is 8.5 ≦ [Ba] / [Sr ] ≦ 100 .M II is Represents one or more metal elements that can have divalent and trivalent valences, where x, α, and β are 0.04 ≦ x <0.3, 1.5 ≦ α ≦ 2.5, and Represents a number satisfying 3.5 ≦ β ≦ 4.5.)

  At this time, in the formula [1], it is preferable that the [Ba] and [Sr] satisfy 0.5 <{[Ba] / ([Ba] + [Sr])} <1. 2).

  In the formula [1], the [Ba] is preferably 0.5 or more and less than 1. (Claim 3)

Further, in the phosphor of the present invention, it is preferable that the D value represented by the following formula satisfies 0.325 ≦ D ≦ 0.568.
D = ((x−0.33) ² + (y−0.33) ² ) ^1/2
(Here, x and y are the chromaticity coordinate x value and y value in the XYZ color system defined by JIS Z8701, and values obtained from data in the wavelength region of 480 nm to 800 nm of the emission spectrum of the phosphor. .)

Further, in the phosphor of the present invention, when the object color is expressed in the L ^* a ^* b ^* color system, it is preferable that L ^* , a ^* , and b ^* satisfy the following ranges, respectively (claims) Item 5).
L ^* ≧ 90,
a ^* ≦ −20,
b ^* ≧ 30 and
{A ^* / b ^* } ≦ −0.45

  Furthermore, the phosphor of the present invention is preferably obtained by firing the phosphor precursor in the presence of a flux (claim 6).

  Moreover, the phosphor of the present invention is preferably obtained by firing the phosphor precursor in a strongly reducing atmosphere (claim 7).

  Furthermore, it is preferable that the weight median diameter of the phosphor of the present invention is 10 μm or more and 30 μm or less.

  In addition to the element described in the formula [1], the phosphor of the present invention further includes a monovalent element, a divalent element, a trivalent element, a −1 valent element, and a −3 valent element. It is preferable that at least one element selected from the group consisting of elements is contained, and the total content of these elements is 1 ppm or more.

  Furthermore, in addition to the element described in the formula [1], the phosphor of the present invention further includes an alkali metal element, an alkaline earth metal element, zinc (Zn), yttrium (Y), aluminum (Al), and scandium. It is preferable that it contains at least one element selected from the group consisting of (Sc), phosphorus (P), nitrogen (N), rare earth elements and halogen elements, and the total content of these elements is 1 ppm or more. (Claim 10).

  Another subject matter of the present invention is a method for producing the phosphor of the present invention, which comprises a step of firing a phosphor precursor in an atmosphere having an oxygen concentration of 100 ppm or less. It resides in a method (claim 11).

  Still another subject matter of the present invention is a method for producing a phosphor according to the present invention, comprising a step of firing a phosphor precursor in the presence of solid carbon. (Claim 12).

  Still another subject matter of the present invention lies in a phosphor-containing composition comprising the phosphor of the present invention and a liquid medium (claim 13).

  Still another subject matter of the present invention includes a first light emitter and a second light emitter that emits visible light when irradiated with light from the first light emitter. The present invention resides in a light emitting device comprising at least one of the phosphors of the invention as a first phosphor (claim 14).

  In this case, it is preferable that the second phosphor includes, as the second phosphor, one or more phosphors having emission peak wavelengths different from those of the first phosphor (claim 15).

  Further, the first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm, and the second light emitter has a light emission peak in a wavelength range of 570 nm to 780 nm as the second phosphor. It is preferable to contain at least one kind of phosphor having the above (claim 16).

  The first light emitter has a light emission peak in a wavelength range of 300 nm to 420 nm, and the second light emitter has a light emission peak in a wavelength range of 420 nm to 490 nm as the second phosphor. It is preferable to contain at least one kind of phosphor having an emission peak and at least one kind of phosphor having an emission peak in a wavelength range of 570 nm to 780 nm.

  Further, the first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm, and the second light emitter is a light emission peak in a wavelength range of 580 nm to 620 nm as the second phosphor. It is preferable to contain at least one kind of phosphor having the above (claim 18).

  Still another subject matter of the present invention lies in an image display device comprising the light emitting device of the present invention as a light source (claim 19).

  Still another subject matter of the present invention lies in an illuminating device comprising the light emitting device of the present invention as a light source (claim 20).

  ADVANTAGE OF THE INVENTION According to this invention, it is a fluorescent substance which emits green fluorescence, Comprising: The fluorescent substance with a comparatively short light emission peak wavelength, a half value width is narrow, and high brightness | luminance is provided. Further, by using a composition containing this phosphor, a light-emitting device with high efficiency and high characteristics can be obtained. This light-emitting device is preferably used because it can realize an image display device having a wide color reproduction range, particularly in the use of an image display device such as a display. Moreover, according to the manufacturing method of the fluorescent substance of this invention, the fluorescent substance of this invention can be manufactured favorable.

  Hereinafter, the present invention will be described in detail, but the present invention is not limited to the following exemplifications and embodiments, and can be arbitrarily modified and implemented without departing from the gist thereof.

In the composition formula of the phosphors in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed separated by commas (,), one or two or more of the listed elements may be included in any combination and composition. However, the total of the elements shown in parentheses is 1 mol. For example, the composition formula “(Ba, Sr, Ca) Al ₂ O ₄ : Eu” is expressed by “BaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “CaAl ₂ O ₄ : Eu”. If: the _{"Ba 1-x Sr x Al 2} O 4 Eu ": the _{"Ba 1-x Ca x Al 2} O 4 Eu ": a _{"Sr 1-x Ca x Al 2} O 4 Eu " _{"Ba 1-xy Sr x Ca y} Al 2 O 4: Eu " and all assumed to generically indicated (in the above formula, 0 <x <1,0 <y <1,0 <x + y <1.)

  Further, the relationship between the color name and the chromaticity coordinates in this specification is all based on the JIS standard (JISZ8110 and Z8701).

[1. Phosphor]
The phosphor of the present invention has a composition that satisfies the following rules.

[1-1. Composition of phosphor]
The phosphor of the present invention is characterized by having a chemical composition represented by the following formula [1].

(M ^I _(1-x) M ^II _x ) _α SiO _β [1]
(Wherein [1], M ^I is, Ba, Sr, Ca, selected from the group consisting of Zn and Mg, represents two or more elements including at least Ba and Sr. However, Ba and for the entire M ^I If Sr molar ratio of which is respectively [Ba] and [Sr], is in the range of [Ba] / value represented by [Sr] is 8.5 ≦ [Ba] / [Sr ] ≦ 100 .M II is Represents one or more metal elements that can have divalent and trivalent valences, where x, α, and β are 0.04 ≦ x <0.3, 1.5 ≦ α ≦ 2.5, and Represents a number satisfying 3.5 ≦ β ≦ 4.5.)

In the formula [1], M ^I represents two or more elements selected from the group consisting of Ba, Sr, Ca, Zn and Mg. However, M ¹ requires at least Ba and Sr. Therefore, M ^I may contain only Ba and Sr, and in addition to Ba and Sr, one or more elements selected from the group consisting of Ca, Zn and Mg may be used in any combination and ratio. You may have together.

Here, when the molar ratios of Ba and Sr to the entire M ^I are [Ba] and [Sr], respectively, the relative ratio between [Ba] and [Sr], that is, the value represented by [Ba] / [Sr]. However, it is usually 8.5 or more, especially 9 or more, particularly 10 or more, and usually 100 or less, especially 50 or less, particularly 25 or less. If the value of [Ba] / [Sr] is too small (that is, the ratio of Ba is too small), the emission peak wavelength of the phosphor tends to shift to the longer wavelength side and the half-value width tends to increase. On the other hand, if the value of [Ba] / [Sr] is too large (that is, the ratio of Ba is too large), the emission peak wavelength of the phosphor tends to shift to the short wavelength side.

The molar ratio of Ba to the total M ^I (ie, [Ba]) is usually 0.5 or more, particularly 0.55 or more, more preferably 0.6 or more, and usually less than 1, particularly 0.97 or less, A range of 0.9 or less, particularly 0.8 or less is preferred. If the molar ratio of Ba is too high, the emission peak wavelength tends to shift to the short wavelength side. On the other hand, if the molar ratio of Ba is too low, the light emission efficiency tends to decrease.

  The ratio of [Ba] to the sum of [Ba] and [Sr], that is, the value represented by [Ba] / ([Ba] + [Sr]) is usually larger than 0.5, more preferably 0.8 or more. Further, it is preferably in the range of 0.9 or more, usually less than 1, particularly 0.98 or less, more preferably 0.97 or less. If the value of [Ba] / ([Ba] + [Sr]) is too small (that is, the ratio of Ba is too small), the emission peak wavelength of the phosphor shifts to the longer wavelength side, and the half-value width increases. Tend. On the other hand, if the value of [Ba] / ([Ba] + [Sr]) is too large (that is, the ratio of Ba is too large), the emission peak wavelength of the phosphor tends to shift to the short wavelength side.

When M ^I contains Ca, the molar ratio of the Ca amount to the total amount of Sr is usually 10% or less, preferably 5% or less, and more preferably 2% or less. Ca is usually present in the phosphor by substituting Sr, but if the ratio of the amount of substitution by Ca is too high, the emission tends to be yellowish and the luminous efficiency tends to decrease.

  Further, Si may be partially substituted by other elements such as Ge. However, from the standpoint of green emission intensity and the like, it is preferable that the ratio of Si substituted by other elements is as low as possible. Specifically, other elements such as Ge may be contained in an amount of 20 mol% or less of Si, and it is more preferable that all are made of Si.

In the formula [1], M ^II is listed as an activator element and represents one or more metal elements that can have a divalent and trivalent valence. Specific examples include transition metal elements such as Cr and Mn; rare earth elements such as Eu, Sm, Tm, and Yb. M ^II may contain only one of these elements, or may contain two or more of them in any combination and ratio. Among them, as the M ^II Sm, Eu, Yb are preferred, Eu is particularly preferable. Further, the molar ratio of the divalent element to the entire M ^II (the sum of the divalent element and the trivalent element) is usually 0.5 or more, preferably 0.7 or more, more preferably 0.8 or more, Usually, it is less than 1, and the closer to 1, the better. If the molar ratio of the divalent element to the entire M ^II is too low, the light emission efficiency tends to decrease. This is because a divalent element and a trivalent element are taken into the crystal lattice, but it is considered that the trivalent element absorbs emission energy in the crystal.

In the formula [1], x is a number representing the number of moles of M ^II , specifically, usually 0.04 or more, more preferably 0.05 or more, particularly preferably 0.06 or more, Usually, it represents a number of less than 0.3, preferably 0.2 or less, more preferably 0.15 or less. If the value of x is too small, the emission intensity tends to decrease. On the other hand, if the value of x is too large, the emission intensity tends to decrease.

  In the formula [1], α is preferably close to 2, but is usually 1.5 or more, preferably 1.7 or more, more preferably 1.8 or more, and usually 2.5 or less, preferably 2 .2 or less, more preferably a number in the range of 2.1 or less. If the value of α is too small or too large, heterogeneous crystals appear, and the light emission characteristics tend to deteriorate.

  In the formula [1], β is usually 3.5 or more, preferably 3.8 or more, more preferably 3.9 or more, and usually 4.5 or less, preferably 4.4 or less, more preferably 4 Represents a number in the range of 1 or less. If the value of β is too small or too large, heterogeneous crystals appear and the light emission characteristics tend to deteriorate.

In addition to the elements described in the formula [1], that is, M ^I , M ^II , Si (silicon) and O (oxygen), the phosphor of the present invention further includes a monovalent element and a divalent element. At least one element selected from the group consisting of a trivalent element, a −1 valent element, and a −3 valent element (hereinafter referred to as “trace element” as appropriate) may be contained.

  Among these, as trace elements, alkali metal elements, alkaline earth metal elements, zinc (Zn), yttrium (Y), aluminum (Al), scandium (Sc), phosphorus (P), nitrogen (N), rare earth elements, And at least one element selected from the group consisting of halogen elements.

  The total content of the trace elements is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less. When the phosphor of the present invention contains plural kinds of trace elements, the total amount thereof satisfies the above range.

  Moreover, the phosphor of the present invention may contain one or more elements selected from the group consisting of Tb, Ag, La, Sm, and Pr in addition to the above elements. Among these, it is preferable to contain Tb and / or Pr.

  When the phosphor of the present invention contains Tb, the luminance maintenance rate at high temperature is improved and the temperature characteristics are improved. Furthermore, durability when a light emitting device described later is configured is improved, and lighting can be performed for a long time.

The content of Tb is usually 0.0001 mol% or more, particularly 0.001 mol% or more, more preferably 0.01 mol% or more, and usually 5 mol% or less, especially 1 mol, per 1 mol of the phosphor. % Or less, more preferably 0.5 mol% or less.
If the Tb content is too large, the temperature characteristic improving effect tends to decrease, and if the Tb content is too small, the durability improving effect may decrease.

Further, when the phosphor of the present invention contains Pr, the external quantum efficiency is improved.
The content of Pr is usually 0.0001 mol% or more, especially 0.001 mol% or more, more preferably 0.01 mol% or more, and usually 5 mol% or less, especially 1 mol with respect to 1 mol of the phosphor. % Or less, more preferably 0.5 mol% or less.
When the content of Pr is too large, concentration quenching tends to occur and the brightness tends to decrease. When the content of Pr is too small, the external quantum efficiency improvement effect may decrease.

  The phosphor of the present invention may contain Al in addition to the above elements. The Al content is usually 1 ppm or more, preferably 5 ppm or more, more preferably 10 ppm or more, and usually 500 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less.

  The phosphor of the present invention may contain B (boron) in addition to the above elements. The content of B is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less.

  The phosphor of the present invention may contain Fe in addition to the above elements. The Fe content is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less.

  The phosphor of the present invention may contain N in addition to the above elements. The content of N is usually 10 mol% or less, preferably 5 mol% or less, more preferably 3 mol% or less with respect to the amount of oxygen contained in the phosphor.

[1-2. Characteristics of phosphor
The specific characteristic phosphor of the present invention preferably has the characteristics described below. In the following, physical properties such as emission spectrum, chromaticity coordinates, object color, excitation wavelength, weight median diameter, and crystallite diameter are measured at room temperature (25 ° C.).

<Characteristics related to emission spectrum>
In view of the use as a green phosphor, the phosphor of the present invention preferably has the following characteristics when an emission spectrum is measured when excited with light having a peak wavelength of 400 nm or 455 nm.

First, the phosphor of the present invention is preferably a green phosphor whose emission peak wavelength λ _p is a relatively short wavelength. Specifically, the emission peak wavelength λ _p (nm) in the aforementioned emission spectrum is usually 510 nm or more, preferably 515 nm or more, more preferably 518 nm or more, and usually 530 nm or less, preferably 525 nm or less, more preferably 522 nm. The range is as follows. When the emission peak wavelength λ _p is too short, it tends to be bluish, while when it is too long, it tends to be yellowish, and the characteristics as green light may deteriorate.

The relative intensity of the emission peak of the phosphor of the present invention (hereinafter sometimes referred to as “relative emission peak intensity”) is usually 75 or more, preferably 85 or more, more preferably 95 or more. In addition, this relative light emission peak intensity represents the light emission intensity when exciting BaMgAl ₁₀ O ₁₇ : Eu (product number LP-B4) manufactured by Kasei Optonics Co., Ltd. at 365 nm as 100. A higher relative emission peak intensity is preferred.

  Further, the phosphor of the present invention has a characteristic that the emission peak half width (hereinafter referred to as “FWHM” as appropriate) in the above-described emission spectrum is narrow. A narrow FWHM means that the color purity is excellent, and for example, the phosphor is excellent in applications such as a backlight.

  Specifically, the FWHM of the phosphor of the present invention is usually 10 nm or more, preferably 20 nm or more, more preferably 25 nm or more, and usually 75 nm or less, preferably 70 nm or less. If the FWHM is too narrow, the luminance may decrease. On the other hand, if the FWHM is too wide, the color purity may decrease.

In order to excite the phosphor with light having a peak wavelength of 400 nm or 455 nm, for example, a GaN-based light emitting diode can be used.
In addition, the measurement of the emission spectrum of the phosphor and the calculation of the emission peak wavelength, peak relative intensity, and peak half width are, for example, a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (Hamamatsu Photonics) as a spectrum measurement device. And a fluorescence measuring apparatus (manufactured by JASCO Corporation).

<Absorption efficiency α _q , internal quantum efficiency η _i , and external quantum efficiency η _o >
(Absorption efficiency α _q )
(Which may be expressed by the following "alpha _q".) Absorption efficiency, compared photon number of the excitation light source (corresponding to "first phosphor" later.) Emitted light (excitation light), phosphor It means the ratio of the number of photons to be absorbed. In the following description, “photon” may be referred to as “photon”.

The phosphor of the present invention is more preferable as its absorption efficiency α _q is higher.
Specifically, the absorption efficiency α _q when the phosphor of the present invention is excited with light having a peak wavelength of 400 nm or 455 nm is usually 0.55 or more, preferably 0.6 or more, more preferably 0.75 or more. It is desirable. When the absorption efficiency alpha _q of the phosphor is too low, the excitation light quantity required to obtain a predetermined emission increases, there is a tendency that energy consumption increases.
A method for measuring the absorption efficiency α _q of the phosphor is as described later.

(Internal quantum efficiency η _i )
The internal quantum efficiency (hereinafter sometimes referred to as “η _i ”) means the ratio of the number of photons emitted by the phosphor to the number of photons of excitation light absorbed by the phosphor.

The phosphor of the present invention is preferably as its internal quantum efficiency η _i is higher.
Specifically, the internal quantum efficiency η _i when the phosphor of the present invention is excited with light having a peak wavelength of 400 nm or 455 nm is usually 0.57 or more, preferably 0.69 or more, more preferably 0.79 or more. It is desirable to be. If the internal quantum efficiency η _i of the phosphor is too low, the amount of excitation light necessary to obtain predetermined light emission tends to increase and the energy consumption tends to increase.
A method for measuring the internal quantum efficiency η _i of the phosphor is as described later.

(External quantum efficiency η _o )
The external quantum efficiency (hereinafter sometimes referred to as “η _o ”) is a value representing the ratio of the number of emitted photons of a phosphor to the number of photons of excitation light, and the absorption efficiency α _q and the internal quantum This corresponds to the product of efficiency η _i . That is, the external quantum efficiency η _o is defined by the following equation.
(External quantum efficiency η _o ) = (internal quantum efficiency η _i ) × (absorption efficiency α _q )

The phosphor of the present invention preferably has a high external quantum efficiency η _o .
Specifically, the external quantum efficiency η _o when the phosphor of the present invention is excited with light having a peak wavelength of 400 nm or 455 nm is usually 0.42 or more, preferably 0.50 or more, more preferably 0.55 or more, More preferably, it is 0.65 or more. When the external quantum efficiency eta _o of a phosphor is low, the amount of excitation light required to obtain a predetermined emission increases, there is a tendency that energy consumption increases.
The method for measuring the external quantum efficiency η _o of the phosphor is as described later.

(Measurement method of absorption efficiency α _q , internal quantum efficiency η _i , and external quantum efficiency η _o )
A method for obtaining the absorption efficiency α _q , internal quantum efficiency η _i and external quantum efficiency η _o of the phosphor will be described below.

  First, a phosphor sample to be measured (for example, a phosphor powder) is packed in a cell with a sufficiently smooth surface so that measurement accuracy is maintained, and is attached to a condenser such as an integrating sphere. The use of a condenser such as an integrating sphere makes it possible to count all the photons reflected by the phosphor sample and the photons emitted from the phosphor sample due to the fluorescence phenomenon. This is to eliminate the photons that fly away.

  A light emission source for exciting the phosphor sample is attached to the light collecting device. For example, an Xe lamp or the like is used as the light source. Further, adjustment is performed using a filter, a monochromator (diffraction grating spectrometer), or the like so that the emission peak wavelength of the light emission source is monochromatic light of, for example, 405 nm or 455 nm.

  The phosphor sample to be measured is irradiated with light from the light emission source whose emission peak wavelength is adjusted, and a spectrum including light emission (fluorescence) and reflected light is measured with a spectrometer (for example, MCPD7000 manufactured by Otsuka Electronics Co., Ltd.). taking measurement. The spectrum measured here is actually reflected light that has not been absorbed by the phosphor among the light from the excitation light source (hereinafter simply referred to as “excitation light”), and the phosphor is excited light. And light of another wavelength (fluorescence) emitted by the fluorescence phenomenon. That is, the excitation light region corresponds to the reflection spectrum, and the longer wavelength region corresponds to the fluorescence spectrum (sometimes referred to herein as the emission spectrum).

The absorption efficiency α _q is obtained as a value obtained by dividing the number of photons _Nabs of the excitation light absorbed by the phosphor sample by the total number of photons N of the excitation light. The specific calculation procedure is as follows.

First, the total photon number N of the latter excitation light is obtained as follows.
That is, a white reflector such as a material having a reflectance R of almost 100% with respect to excitation light, for example, “Spectralon” manufactured by Labsphere (having a reflectance R of 98% with respect to 450 nm excitation light) is measured. as it was attached to the above-mentioned condenser in an arrangement similar to the phosphor sample, using a spectroscopic measuring device for measuring the reflection spectrum (the reflection spectrum hereinafter referred to as "I _ref (lambda)".).

From this reflection spectrum I _ref (λ), a numerical value represented by the following (formula I) is obtained. The numerical value represented by the following (formula I) is proportional to the total photon number N of the excitation light.

Note that the integration interval of the above (formula I) may be limited to only an interval in which I _ref (λ) has a significant value.

On the other hand, number N _abs of the photons in the excitation light that is absorbed in the phosphor sample is proportional to the amount calculated by the following equation (II).

In the above (Formula II), “I (λ)” represents a reflection spectrum when the phosphor sample to be measured for the absorption efficiency α _q is attached to the light collector.

  Further, the integration interval of the above (formula II) is the same as the integration interval defined by the above (formula I). By limiting the integration interval in this way, the second term in the above (formula II) is a numerical value corresponding to the number of photons generated when the phosphor sample to be measured reflects excitation light, that is, the measurement target. This is a numerical value corresponding to the number of photons excluding photons derived from the fluorescence phenomenon among all photons generated from the phosphor sample. Since the actual spectrum measurement value is generally obtained as digital data divided by a certain finite bandwidth with respect to λ, the integration of (Equation I) and (Equation II) above is based on the sum based on the bandwidth. I want.

From the above, the absorption efficiency α _q can be obtained by the following equation.
Absorption efficiency α _q = N _abs / N = (Formula II) / (Formula I)

Next, a method for obtaining the internal quantum efficiency η _i will be described.
The internal quantum efficiency η _i is a value obtained by dividing the number N _PL of photons derived from the fluorescence phenomenon by the number of photons N _abs absorbed by the phosphor sample.

Here, _NPL is proportional to the amount obtained by the following (formula III).

The integration interval of the above (formula III) is limited to the wavelength range of photons derived from the fluorescence phenomenon of the phosphor sample. This is because the contribution of photons reflected from the phosphor sample is removed from I (λ).
Specifically, the lower limit of the integration interval of (Equation III) takes the upper end of the integration interval of (Equation I), and the upper limit of the integration interval is a range that is necessary and sufficient to include photons derived from fluorescence. To do.

As described above, the internal quantum efficiency α _q is obtained by the following equation.
η _i = (Formula III) / (Formula II)

It should be noted that the point of integration from the spectrum that has become digital data is the same as when the absorption efficiency α _q is obtained.

The external quantum efficiency η _o can be obtained by taking the product of the absorption efficiency α _q obtained by the above procedure and the internal quantum efficiency η _i .

The external quantum efficiency η _o can also be obtained from the following relational expression.
η _o = (Formula III) / (Formula I)
That is, the external quantum efficiency η _o is a value obtained by dividing the number N _PL of photons derived from fluorescence by the total number N of photons of excitation light.

<Characteristics of phosphor surface>
In the phosphor of the present invention, it is preferable that at least a part of the surface, preferably substantially the whole of the surface, is made of a substance containing oxygen.

For example, if the phosphor of the present invention is an oxide phosphor or an oxynitride phosphor, the surface of the phosphor is naturally a substance containing oxygen. In addition, the surface of the phosphor can be coated with an oxide phosphor or an oxynitride phosphor with calcium phosphate or silica.
On the other hand, when the phosphor of the present invention is a nitride phosphor or a sulfide phosphor, the surface is coated with calcium phosphate, silica or the like, and at least a part of the surface of the phosphor is a substance containing oxygen. It is preferable. However, since the surface of the phosphor may be oxidized during the crushing process or the like and an oxide film may be formed, in this case, it is not necessary to actively coat.

  In the case where the phosphor containing the oxygen-containing substance on the surface of the phosphor of the present invention is layered, the thickness of the layer is usually 10 nm or more, preferably 30 nm or more, and usually 1 μm or less, preferably 500 nm or less. It is desirable to be.

<Chromaticity coordinates>
The emission color of the phosphor of the present invention can be expressed by one of the CIE chromaticity coordinates, the x, y color system (CIE 1931 color system), and the CIE chromaticity coordinates x and y based on JIS Z8701. The value should satisfy the following rules.

Specifically, the CIE chromaticity coordinate x of the phosphor of the present invention is usually 0.210 or more, preferably 0.240 or more, more preferably 0.263 or more, and usually 0.330 or less, preferably It is desirable that the range be 0.310 or less, more preferably 0.300 or less.
Further, the CIE chromaticity coordinate y of the phosphor of the present invention is usually 0.480 or more, preferably 0.490 or more, more preferably 0.495 or more, and usually 0.670 or less, preferably 0.8. It is desirable that the range be 660 or less, more preferably 0.655 or less.
When the values of the CIE chromaticity coordinates x and y satisfy the above range, there is an advantage that the color reproduction range is widened during white light synthesis.
The values of CIE chromaticity coordinates x and y of the phosphor can be calculated by calculating according to JIS Z8724 from the emission spectrum in the wavelength range of 480 nm to 800 nm.

Further, the phosphor of the present invention has a D value represented by the following formula of usually 0.325 or more, preferably 0.328 or more, particularly preferably 0.33 or more, and usually 0.568 or less, Preferably it is 0.4 or less, particularly preferably 0.34 or less.
D = ((x−0.33) ² + (y−0.33) ² ) ^1/2
In the above formula, x and y are the chromaticity coordinate x value and y value in the XYZ color system defined by JIS Z8701, and are values obtained from data in the wavelength region of 480 nm to 800 nm of the emission spectrum of the phosphor. It is. When the D value is in the above range, there is an advantage that the color reproduction range is widened when the image display apparatus is used.

<Object color>
In the phosphor of the present invention, when the object color is represented by the L ^* a ^* b ^* color system (CIE 1976 color system), the L ^* value, the a ^* value, and the b ^* value satisfy the following expressions. It is preferable.
L ^* ≧ 90
a ^* ≦ −20
b ^* ≧ 30
{A ^* / b ^* } ≦ −0.45

  Since the phosphor of the present invention has an object color that satisfies the above conditions, a light emitting device with high luminous efficiency can be realized when used in a light emitting device described later.

Specifically, the upper limit value of a ^* of the phosphor of the present invention is usually −20 or less, preferably −22 or less, more preferably −24 or less, and particularly preferably −30 or less. A phosphor with a ^* too large tends to reduce the total luminous flux. Also, from the viewpoint of increasing luminance, it is desirable that the value of a ^* is small.

In addition, b ^* of the phosphor of the present invention is usually 30 or more, preferably 40 or more, more preferably 45 or more, and particularly preferably 50 or more. If b ^* is too small, the luminance tends to decrease. On the other hand, the upper limit of b ^* is theoretically 200 or less, but is usually preferably 120 or less. If b ^* is too large, the emission wavelength tends to shift to the longer wavelength side and the luminance tends to decrease.

The ratio of a ^* and b ^* of the phosphor of the present invention, that is, the value represented by a ^* / b ^* is usually −0.45 or less, preferably −0.5 or less, more preferably −0. The range is 55 or less. When the value of a ^* / b ^* is too large, the object color tends to be yellowish and the luminance tends to decrease.

Further, L ^* of the phosphor of the present invention is usually 90 or more, preferably 95 or more. If the value of L ^* is too small, the light emission tends to be weak. On the other hand, the upper limit value of L ^* generally does not exceed 100 because it deals with an object that does not emit light by irradiation light. However, the phosphor of the present invention emits light that has been excited by irradiation light as reflected light. In some cases, the value of L ^* exceeds 100. Specifically, the upper limit value of L ^* of the phosphor of the present invention is usually 115 or less.

The object color of the phosphor of the present invention can be measured by using, for example, a commercially available object color measuring device (for example, CR-300 manufactured by Minolta).
The object color means a color when light is reflected by the object. In the present invention, it measured (i.e., the phosphor) light (a white light source. For example, it is possible to use a standard light D _65.) Which is determined was irradiated with the reflected light obtained was dispersed by filter Thus, the values of L ^* , a ^* , and b ^* are obtained.
The object color is related to the degree of reduction of the phosphor material (for example, expressed as a ratio of the molar ratio of the divalent element to the whole M ^II ), and when the degree of reduction is high (for example, the divalent to the whole M ^II When the molar ratio of the elements is high), it is considered that the object color is in the above range. As will be described later, when the phosphor raw material is produced according to the production method of the present invention, such as by firing the phosphor raw material in a strongly reducing atmosphere such as the presence of solid carbon, a phosphor having an object color in the above range can be obtained.

<Characteristics related to excitation wavelength>
The excitation wavelength of the phosphor of the present invention is not particularly limited, but is usually 300 nm or more, particularly 350 nm or more, more preferably 380 nm or more, and usually 500 nm or less, especially 480 nm or less, more preferably 470 nm or less. It is preferable that For example, if it can be excited by light in a blue region and / or light in a near ultraviolet region, it can be suitably used for a light emitting device using a semiconductor light emitting element or the like as a first light emitter.

  The excitation spectrum can be measured at room temperature, for example, 25 ° C., using a fluorescence spectrophotometer F-4500 type (manufactured by Hitachi, Ltd.). The excitation peak wavelength can be calculated from the obtained excitation spectrum.

<Weight median diameter>
The phosphor of the present invention preferably has a weight median diameter in the range of usually 10 μm or more, especially 12 μm or more, particularly 15 μm or more, and usually 30 μm or less, especially 25 μm or less, particularly 20 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of a dispenser or the like to occur. The weight median diameter of the phosphor of the present invention can be measured using a device such as a laser diffraction / scattering particle size distribution measuring device.

<Crystallite diameter>
Further, the phosphor of the present invention is preferably as the crystallite diameter is larger, and is usually 20 nm or more, and preferably 100 nm or more. Here, the crystallite diameter can be obtained by measuring a half width in powder X-ray diffraction. It is believed that non-radiative deactivation occurs at the interface between crystallites, and conversion of luminescence energy into thermal energy occurs. When the crystallite is large, the crystallite interface is reduced, so that the conversion to heat energy is small and the luminance is increased.

<Temperature characteristics>
In addition, as described above, some phosphors of the present invention have excellent temperature characteristics, such as when containing Tb. Specifically, the ratio of the emission peak intensity value in the emission spectrum at 100 ° C. to the luminance at 25 ° C. when irradiated with light having a wavelength of 455 nm is usually 50% or more, preferably 60% or more. Especially preferably, it is 70% or more.

  In addition, since the emission intensity of ordinary phosphors decreases with increasing temperature, it is unlikely that the ratio exceeds 100%, but it may exceed 100% for some reason. However, if it exceeds 150%, the color shift tends to occur due to temperature change.

  In the case of measuring the temperature characteristics, for example, an MCPD7000 multi-channel spectrum measuring device manufactured by Otsuka Electronics as a light emission spectrum device, a stage having a cooling mechanism by a Peltier element and a heating mechanism by a heater, and a 150 W xenon lamp as a light source. It can measure as follows using the apparatus provided. A cell containing a phosphor sample is placed on the stage, and the temperature is changed in the range of 20 ° C to 180 ° C. It is confirmed that the surface temperature of the phosphor is constant at a predetermined temperature. Next, the phosphor is excited by light of 455 nm extracted from the light source by the diffraction grating and the emission spectrum is measured. The emission peak intensity is obtained from the measured emission spectrum. Here, as the measurement value of the surface temperature of the phosphor, a value corrected using the temperature measurement value by the radiation thermometer and the thermocouple is used.

<Durability>
The phosphor of the present invention is also excellent in durability. In particular, as described above, when Tb or the like is contained, the durability is more excellent. Specifically, when a light emitting device is configured using the phosphor of the present invention, the value of “green peak emission intensity / blue peak emission intensity” immediately after the start of lighting (0 hour) is 100%. The value of “green peak emission intensity / blue peak emission intensity” for 1000 hours is usually 85% or more, preferably 90% or more, more preferably 95% or more.

  The durability can be measured by the following procedure, for example. Immediately after the lighting device is turned on (hereinafter referred to as “0 hour”), the emission spectrum and chromaticity coordinates are measured using a fiber multichannel spectrometer (USB2000 manufactured by Ocean Optics). Next, using an aging device, LED AGING SYSTEM 100ch LED environmental test device (YEL-51005, manufactured by Yamakatsu Electronics Co., Ltd.), the light emitting device was continuously driven at a drive current of 20 mA under conditions of 85 ° C. and relative humidity of 85%. Then, the light is turned on for 1000 hours, and the emission spectrum and chromaticity coordinates are measured again using a fiber multichannel spectrometer (USB2000 manufactured by Ocean Optics). In each measured emission spectrum, the emission intensity of the green peak (derived from the phosphor) relative to the emission intensity of the blue peak (derived from the LED), that is, “green peak emission intensity / blue peak emission intensity”. And the value of “green peak emission intensity / blue peak emission intensity” for 1000 hours when the value of “green peak emission intensity / blue peak emission intensity” at 0 hour is 100% is obtained. .

[1-3. Method for producing phosphor]
The raw materials for obtaining the phosphor of the present invention, the phosphor production method, and the like are as follows.

The method for producing the phosphor of the present invention is not particularly limited. For example, the raw material of the metal element M ^I (hereinafter referred to as “M ^I source” as appropriate), the Si raw material (hereinafter referred to as “Si source” as appropriate), and The raw material of the element M ^II that is the activator element (hereinafter referred to as “M ^II source” as appropriate) is weighed and mixed (mixing step), and the resulting mixture (this is sometimes referred to as “phosphor precursor”). ) Under predetermined firing conditions (firing step) and, if necessary, pulverization, washing, surface treatment and the like can be performed.

<Phosphor material>
Examples of the M ^I source, Si source, and M ^II source used in the production of the phosphor of the present invention include oxides, hydroxides, carbonates, nitrates, sulfates of the respective elements of M ^I , Si, and M ^II , Examples thereof include oxalates, carboxylates and halides. From these compounds, the reactivity to the composite oxide, the low generation amount of NO _x , SO _{x and the} like during firing may be selected as appropriate.

Specific examples of the M ^I source are listed for each type of M ^I metal as follows.

Specific examples of the Ba _{source, BaO, Ba (OH) 2} · 8H 2 O, BaCO 3, Ba (NO 3) 2, BaSO 4, Ba (C 2 O 4) · 2H 2 O, Ba (OCOCH 3) ₂ and BaCl ₂ . Of these, BaCO ₃ , BaCl _{2 and the} like are preferable, and BaCO ₃ is particularly preferable from the viewpoint of handling. This is because the stability in the air is good, and it is easily decomposed by heating, so that undesired elements hardly remain and it is easy to obtain high-purity raw materials. When carbonate is used as a raw material, it is preferable to pre-calcinate the carbonate and use it as a raw material.

Specific examples of the Sr source include SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (C ₂ O ₄ ) · H ₂ O, Sr (OCOCH ₃ ). ₂ · 0.5H ₂ O, SrCl _{2 and the} like. Of these, SrCO ₃ , SrCl _{2 and the} like are preferable, and SrCO ₃ is particularly preferable. This is because the stability in the air is good, it decomposes easily by heating, it is difficult for undesired elements to remain, and it is easy to obtain high-purity raw materials. When carbonate is used as a raw material, it is preferable to pre-calcinate the carbonate and use it as a raw material.

Specific examples of the Ca source include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H ₂ O, Ca (C ₂ O ₄ ) · H ₂ O, and Ca. (OCOCH ₃ ) ₂ .H ₂ O, CaCl _{2 and the} like. Of these, CaCO ₃ , CaCl _{2 and the} like are preferable. When carbonate is used as a raw material, it is preferable to pre-calcinate the carbonate and use it as a raw material.

Specific examples of the Zn source include ZnO, Zn (C ₂ O ₄ ) · 2H ₂ O, ZnSO ₄ · 7H ₂ O, and the like.

Specific examples of the Mg source include MgCO ₃ , MgO, MgSO ₄ , Mg (C ₂ O ₄ ) · 2H ₂ O, and the like. When carbonate is used as a raw material, it is preferable to pre-calcinate the carbonate and use it as a raw material.

Any one of these ^MI sources may be used, or two or more may be used in any combination and ratio.

Specific examples of the Si source include SiO ₂ , H ₄ SiO ₄ , Si (OCOCH ₃ ) _{4 and the} like. Of these, SiO ₂ is preferable.
Any one of these Si sources may be used, or two or more thereof may be used in any combination and ratio.

Among the M ^II sources, specific examples of Eu sources include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (C ₂ O ₄ ) ₃ , EuCl ₂ , EuCl ₃ , Eu (NO ₃ ) _3. 6H ₂ O, and the like. Of these, Eu ₂ O ₃ , EuCl _{2 and the} like are preferable.
Specific examples of the Sm source, the Tm source, the Yb source, and the like include compounds in which Eu is replaced with Sm, Tm, Yb, etc. in the respective compounds listed as specific examples of the Eu source.
Any one of these M ^II sources may be used, or two or more of them may be used in any combination and ratio.

  Moreover, you may use the compound containing another element as a raw material according to the composition of the fluorescent substance of this invention made into the objective.

For example, when a phosphor having a composition containing Ge is manufactured, specific examples of the Ge source include GeO ₂ , Ge (OH) ₄ , Ge (OCOCH ₃ ) ₄ , GeCl _{4, and the} like. Of these, GeO _{2 and the} like are preferable.

For example, when producing a phosphor having a composition containing Tb, specific examples of the Tb source include Tb ₄ O ₇ , TbCl ₃ (including hydrates), TbF ₃ , Tb (NO ₃ ) ₃ .nH _2. O, Tb ₂ (SiO ₄ ) ₃ , Tb ₂ (C ₂ O ₄ ) ₃ · 10H ₂ O, and the like. Among these, Tb ₄ O ₇ , TbCl ₃ and TbF ₃ are preferable, and Tb ₄ O ₇ is more preferable. For example, when a phosphor having a composition containing Pr is manufactured, specific examples of the Pr source include Pr ₂ O ₃ , PrCl ₃ , PrF ₃ , Pr (NO ₃ ) ₃ .6H ₂ O, Pr ₂ (SiO ₄ ). ₃ , Pr ₂ (C ₂ O ₄ ) ₃ · 10H ₂ O, and the like. Among these, Pr ₂ O ₃ , PrCl ₃ , and PrF ₃ are exemplified, and Pr ₂ O ₃ is more preferable. For example, when manufacturing a phosphor having a composition containing Ga, specific examples of the Ga source include Ga ₂ O ₃ , Ga (OH) ₃ , Ga (NO ₃ ) ₃ .nH ₂ O, Ga ₂ (SO ₄ ). ₃ , GaCl _{3 and the} like. For example, when producing a phosphor composition containing Al, as a specific example of the Al source is _{α-Al 2 O 3, γ} -Al 2 O 3, Al 2 O 3 equal, Al (OH) _3, AlOOH, Al (NO ₃ ) ₃ .9H ₂ O, Al ₂ (SO ₄ ) ₃ , AlCl _{3 and the} like can be mentioned. For example, when producing a phosphor having a composition containing P, specific examples of the P source include P ₂ O ₅ , Ba ₃ (PO ₄ ) ₂ , Sr ₃ (PO ₄ ) ₂ , (NH ₄ ) ₃ PO _4. Etc. For example, when producing a phosphor composition containing B, as specific examples of B _{source, B 2 O 3, H 3} BO 3 and the like.
Any one of these compounds containing other elements may be used, or two or more of them may be used in any combination and ratio.

<Mixing process>
The method for mixing the M ^I source, the Si source, and the M ^II source is not particularly limited, and examples thereof include the following (A) dry method and (B) wet method.

(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., pulverization using mortar and pestle, etc., mixer such as ribbon blender, V-type blender and Henschel mixer, or mortar and pestle A dry mixing method in which the above raw materials are pulverized and mixed in combination with mixing.

(B) After adding a solvent or dispersion medium such as water, methanol, ethanol or the like to the above-mentioned raw materials and mixing with a pulverizer, a mortar and pestle, or an evaporating dish and a stirring rod, Wet mixing method of drying by spray drying, heat drying, or natural drying.

<Baking process>
The firing step is usually performed by filling the mixture obtained in the above-described mixing step into a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each phosphor material and firing the mixture. As the material of the heat-resistant container used at the time of firing, for example, ceramics such as alumina, quartz, boron nitride, silicon carbide, silicon nitride, magnesium oxide, metals such as platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, or Examples thereof include alloys containing these as main components and carbon (graphite). Here, the heat-resistant container made of quartz can be used for heat treatment at a relatively low temperature, that is, 1200 ° C. or less, and a preferable use temperature range is 1000 ° C. or less. Of the materials for the heat-resistant container described above, alumina and metal are particularly preferable.

  Although the temperature at the time of baking is arbitrary as long as the phosphor of the present invention is obtained, it is usually 850 ° C. or higher, preferably 950 ° C. or higher, and usually 1400 ° C. or lower, preferably 1350 ° C. or lower. If the firing temperature is too low, the crystal does not grow sufficiently and the particle size may be small. On the other hand, if the firing temperature is too high, the crystal grows too much and the particle size may become too large.

  The pressure at the time of firing is not particularly limited because it varies depending on the firing temperature or the like, but is usually 0.01 MPa or more, preferably 0.1 MPa or more, and usually 200 MPa or less, preferably 100 MPa or less. Among these, the atmospheric pressure to about 1 MPa is industrially preferable in terms of cost and labor.

  The firing time is not particularly limited because it varies depending on the temperature and pressure at the time of firing, but is usually 10 minutes or longer, preferably 1 hour or longer, more preferably 3 hours or longer, more preferably 4 hours or longer, and usually 24 hours. Hereinafter, it is preferably in the range of 15 hours or less.

  The atmosphere during firing is not particularly limited as long as the phosphor of the present invention is obtained, but in the present invention, it is preferable to perform firing in an atmosphere having a low oxygen concentration as described later. The oxygen concentration at the time of firing is preferably 100 ppm or less, more preferably 50 ppm or less, and particularly preferably 20 ppm or less. Ideally, no oxygen is present at all. As a specific example of the atmosphere, it is performed in an atmosphere of only one kind or a mixed atmosphere of two or more kinds of gases such as carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon. Among these, it is preferable to contain reducing gas, such as carbon monoxide and hydrogen, and especially under a nitrogen atmosphere containing hydrogen.

  Here, the hydrogen content contained in the hydrogen-containing nitrogen atmosphere is usually 1% by volume or more, preferably 2% by volume or more, and usually preferably 5% by volume or less, and the most preferable hydrogen content is 4% by volume or less. It is. This is because if the hydrogen content in the atmosphere is too high, there is a risk of explosion, and if it is too low, a sufficient reducing atmosphere cannot be achieved.

  Furthermore, in the present invention, during firing, the firing atmosphere is a reducing atmosphere such as a hydrogen-containing nitrogen atmosphere, and further, the oxygen concentration is lowered by making solid carbon coexist in the reaction system, etc. Although it is preferable, this will be described in detail in the following sections.

(Solid carbon)
To produce the phosphor of the present invention, as the activation element M ^II of the present invention is to contribute ionic state into luminescence (valence), it is preferable to select a suitable atmosphere. For example, it is desirable that at least a part of Eu as an activating element, which is one of preferable M ^II elements that cause green light emission in the phosphor of the present invention, be a divalent ion. Specifically, the ratio of Eu ²⁺ in the total Eu is preferably as high as possible, and is usually 50% or more, preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. However, a compound containing trivalent Eu ions such as Eu ₂ O ₃ is usually used as a raw material for Eu. Therefore, in order to obtain a phosphor that contains Eu ²⁺ that is a divalent ion and emits green light, conventionally, in order to reduce the trivalent ion Eu ³⁺ to the divalent ion Eu ²⁺ , carbon monoxide, Firing was generally performed in some reducing atmosphere such as hydrogen-containing nitrogen or hydrogen. However, even in these firing atmospheres, oxygen derived from raw materials and the like is contained, so that it has been difficult to sufficiently reduce the oxygen concentration. Further, when Sm, Tm, Yb or the like is used as the M ^II element, there are the same problems as in the case of Eu described above.

As a result of the study, the inventors have reduced the trivalent ion of the M ^II element to a divalent ion and simultaneously introduced it into the host crystal, under the condition that solid carbon coexists in addition to the normal reducing atmosphere (that is, It has been found that firing under conditions with a stronger reducing power is effective. As a result, the obtained phosphor has the characteristics that it emits light with high brightness in the wavelength range of 510 nm or more and 542 nm or less as described above, and at the same time, the emission spectrum width is narrow.

Moreover, the object color of the is considered to have become an indicator of reduction degree of M ^II element. By firing in strong reducing atmosphere, M ^II element is sufficiently reduced, the phosphor represented by the formula [1] It is believed that will have a luminous object color of said range.

  The type of solid carbon is not particularly limited, and any type of solid carbon can be used. Examples thereof include carbon black, activated carbon, pitch, coke, graphite (graphite) and the like. The reason why it is preferable to use solid carbon is that oxygen in the firing atmosphere reacts with the solid carbon to generate carbon monoxide gas, and this carbon monoxide further reacts with oxygen in the firing atmosphere to form carbon dioxide. This is because the oxygen concentration in the firing atmosphere can be reduced. Among the examples described above, activated carbon having high reactivity with oxygen is preferable. The shape of the solid carbon includes powder, beads, particles, blocks, etc., but is not particularly limited.

  The amount of solid carbon to be coexisted is usually 0.1% by weight or more, preferably 1% by weight or more, more preferably 10% by weight or more, particularly preferably 30% by weight with respect to the phosphor, although it depends on other firing conditions. % And more preferably 50% by weight or more.

Further, by using a graphite crucible as a firing container, it is possible to obtain the same effect as the coexistence of solid carbon. On the other hand, when using a crucible made of a material other than carbon, such as an alumina crucible, for example, it is preferable that solid carbon such as graphite beads, granules, and blocks coexist separately.
Note that firing is preferably performed under sealed conditions, such as by covering the crucible.

  Note that firing in the presence of solid carbon means that the phosphor raw material and solid carbon need only exist in the same firing container, and it is necessary to mix and fire the phosphor raw material and solid carbon. Absent. Generally, when carbon is mixed in a phosphor product, the black carbon absorbs the light emission of the phosphor, so that the luminous efficiency of the phosphor decreases. As an example of the method of coexisting solid carbon, put solid carbon in a container different from the container containing the phosphor raw material, and place these containers in the same crucible (for example, the upper part of the raw material container Such as placing the solid carbon in the phosphor raw material or placing the solid carbon around the container filled with the phosphor raw material powder. Can be mentioned. In addition, when using a large crucible, it is preferable to sinter solid carbon into the same container as the phosphor material. In any case, the solid carbon is devised so as not to be mixed in the phosphor raw material.

As a technique for obtaining a divalent ion of the M ^II element, in addition to the above-described technique for coexisting solid carbon, or in place of the technique for coexisting solid carbon, the following technique can also be implemented. That is, it is preferable to remove the air present in the crucible at the same time as the raw material powder as much as possible to lower the oxygen concentration. As a specific method, it is preferable that the crucible charged with a predetermined raw material is removed under reduced pressure in a vacuum furnace, and an atmospheric gas used during firing is introduced to restore the pressure. It is more preferable to repeat this operation. Alternatively, an oxygen getter such as Mo can be used as necessary. Further, if safety measures are taken, divalent ions of the M ^II element can also be obtained by firing in a nitrogen atmosphere containing 5% by volume or more of hydrogen.

  The presence of solid carbon in this manner reduces the oxygen concentration in the firing atmosphere, and makes the firing atmosphere a highly reducing atmosphere (that is, a strong reducing atmosphere), thereby obtaining a phosphor with high characteristics. preferable.

(flux)
In the firing step, it is preferable that a flux coexists in the reaction system from the viewpoint of growing good crystals. The type of the flux is not particularly limited, but a compound containing a monovalent element or atomic group and a -1 valent element, a compound containing a monovalent element or atomic group and a -3 valent element or atomic group, Compound containing divalent element and −1 valent element, compound containing 2 valent element and -3 valent element or atomic group, compound containing 3 valent element and −1 valent element In addition, it is preferable to use as the flux a compound selected from the group consisting of a trivalent element and a compound containing a trivalent element or an atomic group.

The monovalent element or atomic group is preferably, for example, at least one element selected from the group consisting of an alkali metal element and an ammonium group (NH ₄ ), and is cesium (Cs) or rubidium (Rb). Is more preferable.
The divalent element is preferably, for example, at least one element selected from the group consisting of an alkaline earth metal element and zinc (Zn), and more preferably strontium (Sr) or barium (Ba). preferable.
The trivalent element is preferably at least one element selected from the group consisting of rare earth elements such as lanthanum (La), yttrium (Y), aluminum (Al), and scandium (Sc). (Y) or aluminum (Al) is more preferable.
The -1 valent element is preferably, for example, at least one element selected from the group consisting of halogen elements, and is preferably chlorine (Cl) or fluorine (F).
The −3 element or atomic group is preferably, for example, a phosphate group (PO ₄ ).

  Among the above, the flux is a trivalent selected from the group consisting of alkali metal halides, alkaline earth metal halides, zinc halides, yttrium (Y), aluminum (Al), scandium (Sc), and rare earth elements. Selected from the group consisting of elemental halides, alkali metal phosphates, alkaline earth metal phosphates, zinc phosphate, yttrium (Y), aluminum (Al), lanthanum (La), and scandium (Sc) It is preferable to use a compound selected from the group consisting of phosphates of trivalent elements.

More specifically, NH ₄ Cl, LiCl, NaCl, KCl, CsCl, CaCl ₂ , BaCl ₂ , SrCl ₂ , YCl ₃ .6H ₂ O (however, it may be an hydrate), ZnCl ₂ , MgCl ₂ .6H ₂ O (but may be hydrated), chlorides such as RbCl, LiF, NaF, KF, CsF, CaF ₂ , BaF ₂ , SrF ₂ , AlF ₃ , MgF ₂ , YF Fluoride such as ₃ ; K ₃ PO ₄ , K ₂ HPO ₄ , KH ₂ PO ₄ , Na ₃ PO ₄ , Na ₂ HPO ₄ , NaH ₂ PO ₄ , Li ₃ PO ₄ , Li ₂ HPO ₄ , LiH ₂ PO ₄ , (NH ₄ ) ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ , (NH ₄ ) H ₂ PO _{4 and} other phosphates.

Of these, LiCl, CsCl, it is preferable to use a _{BaCl 2, SrCl 2, YF 3} , CsCl, it is particularly preferable to use SrCl _2.

  These fluxes may be used alone or in combination of two or more in any combination and ratio, but the following effects can be obtained by using two or more in combination.

  Although it varies depending on the type of flux, firing conditions, and the like, generally, when the flux is allowed to coexist in the phosphor material, crystal growth of the phosphor is promoted and a phosphor having a large particle size tends to be obtained. In addition, the phosphor of the present invention tends to increase in luminance as the particle size increases. From the above, when the flux is allowed to coexist in the phosphor raw material, it seems that the brightness is improved, but it seems preferable. However, if the particle size is too large, the handling property is deteriorated, such as coating unevenness or clogging of the dispenser. There is a tendency.

When two or more kinds of fluxes are used in combination, among the above-mentioned fluxes, use of a compound containing a divalent element such as SrCl ₂ or BaCl ₂ as a flux has an effect of promoting crystal growth. Among the fluxes, it has been clarified by the present invention that when a compound containing a monovalent or trivalent element such as CsCl, LiCl, YCl ₃ .6H ₂ O is used as the flux, there is an effect of suppressing crystal growth. Therefore, when a flux having a crystal growth promoting action and a flux having a crystal growth inhibiting action are used in combination, the weight median that is easy to handle and has high brightness and crystal growth is suppressed due to the synergistic effect of both fluxes. Since a phosphor having a diameter (specifically, 10 μm or more and 25 μm or less) can be obtained, it is particularly preferable.

Preferred combinations when two or more fluxes are used in combination include SrCl ₂ and CsCl, SrCl ₂ and LiCl, SrCl ₂ and YCl ₃ .6H ₂ O, SrCl ₂ , BaCl ₂ and CsCl, etc. Among them, SrCl 2 It is particularly preferable to use ₂ and CsCl in combination.

  The amount of flux used (the total amount used when two or more fluxes are used in combination) varies depending on the type of raw material, the material of the flux, the firing temperature, the atmosphere, etc., but is usually 0.01% by weight or more. Is preferably 0.1% by weight or more, usually 20% by weight or less, and more preferably 10% by weight or less. If the amount of flux used is too small, the effect of flux may not appear. If the amount of flux used is too large, the flux effect will be saturated, the particle size will become too large and the handleability will be poor, it will be incorporated into the host crystal and the emission color may be changed, and the brightness may be reduced. .

  Moreover, when using in combination of 2 or more types of flux, the use ratio (molar ratio) of the compound containing a monovalent or trivalent element is 1 when the number of moles of the compound containing a divalent element is 1. It is usually 0.1 or more, preferably 0.2 or more, and usually 10 or less, preferably 5 or less.

When an appropriate amount of a preferable flux such as SrCl ₂ is used, the present invention can be used even in a weak reducing atmosphere in which solid carbon does not coexist (for example, in a hydrogen-containing nitrogen atmosphere (nitrogen: hydrogen = 96: 4 (volume ratio)). The phosphor can be obtained.

(Primary firing and secondary firing)
The firing step may be divided into primary firing and secondary firing, and the raw material mixture obtained by the mixing step may be first fired first, and then pulverized again with a ball mill or the like, followed by secondary firing.

  The temperature of the primary firing is usually in the range of 850 ° C. or higher, preferably 1000 ° C. or higher, more preferably 1050 ° C. or higher, and usually 1350 ° C. or lower, preferably 1200 ° C. or lower, more preferably 1150 ° C. or lower.

  The primary firing time is usually in the range of 1 hour or longer, preferably 2 hours or longer, more preferably 4 hours or longer, and usually 24 hours or shorter, preferably 15 hours or shorter, more preferably 13 hours or shorter.

  The conditions such as the temperature and time of the secondary firing are basically the same as the conditions described in the above-mentioned columns (Baking conditions), (Solid carbon) and (Flux).

  The flux may be mixed before the primary firing or may be mixed before the secondary firing. Also, the firing conditions such as the atmosphere may be changed between the primary firing and the secondary firing.

<Post-processing>
After the heat treatment in the above-described firing step, washing, drying, pulverization, classification treatment, and the like are performed as necessary.
For the pulverization treatment, pulverizers listed as being usable in the raw material mixing step can be used. The washing can be performed with water such as deionized water, an organic solvent such as methanol or ethanol, an alkaline aqueous solution such as ammonia water, or the like. The classification treatment can be performed by sieving or water sieving, or by using various classifiers such as various air classifiers or vibrating sieves. In particular, when dry classification using a nylon mesh is used, a phosphor with good dispersibility having a weight median diameter of about 20 μm can be obtained.
Moreover, it is preferable to perform a drying process after a washing process. Although there is no restriction | limiting in particular in the method of a drying process, It is preferable to select a drying process method suitably according to the property of fluorescent substance as needed. For example, when the phosphor of the present invention is exposed to a high-temperature and high-humidity atmosphere (for example, hot water) for a long time, a part of the base surface of the phosphor is dissolved, and the dissolved part is carbon dioxide in the air. May react with carbonate to form carbonate. Therefore, when the phosphor of the present invention is subjected to a drying treatment, low temperature drying such as vacuum drying, reduced pressure drying, freeze drying, or short time drying such as spray drying is preferable, and carbon dioxide such as nitrogen or argon gas is used. A method of drying in an atmosphere that does not contain, or a method of air-drying by replacing water with a low-boiling solvent is preferable.

<Surface treatment>
In addition, when manufacturing the light-emitting device by the method described later using the phosphor of the present invention obtained by the above-described procedure, the light-emitting device described later is used to further improve the weather resistance such as moisture resistance. In order to improve the dispersibility of the phosphor in the phosphor-containing part, surface treatment such as coating the surface of the phosphor with a different substance may be performed as necessary.

  Examples of substances that can be present on the surface of the phosphor (hereinafter referred to as “surface treatment substances” as appropriate) include organic compounds, inorganic compounds, glass materials, and the like.

  Examples of the organic compound include acrylic resins, heat-meltable polymers such as polycarbonate, polyamide, and polyethylene, latex, polyorganosiloxane, and the like.

  Examples of inorganic compounds include magnesium oxide, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, tin oxide, germanium oxide, tantalum oxide, niobium oxide, vanadium oxide, boron oxide, antimony oxide, zinc oxide, yttrium oxide, oxide Examples thereof include metal oxides such as lanthanum and bismuth oxide, metal nitrides such as silicon nitride and aluminum nitride, orthophosphates such as calcium phosphate, barium phosphate, and strontium phosphate, and polyphosphates.

  Examples of the glass material include borosilicate, phosphosilicate, and alkali silicate.

  These surface treatment substances may be used alone or in combination of two or more in any combination and ratio.

The phosphor of the present invention that has undergone surface treatment has these surface treatment substances. Examples of the presence of the surface treatment substance include the following.
(I) A mode in which the surface treatment substance constitutes a continuous film and covers the surface of the phosphor of the present invention.
(Ii) A mode in which the surface treatment substance becomes a large number of fine particles and adheres to the surface of the phosphor of the present invention, thereby covering the surface of the phosphor of the present invention.

  The adhesion amount or the coating amount of the surface treatment substance on the surface of the phosphor of the present invention is usually 0.1% by weight or more, preferably 1% by weight or more, more preferably 5%, based on the weight of the phosphor of the present invention. It is desirable that the content is not less than 50% by weight, usually not more than 50% by weight, preferably not more than 30% by weight, more preferably not more than 15% by weight. If the amount of the surface treatment substance relative to the phosphor is too large, the light emission characteristics of the phosphor may be impaired. If the amount is too small, the surface coating will be incomplete, and the moisture resistance and dispersibility will not be improved. There is.

  Further, the film thickness (layer thickness) of the surface treatment substance formed by the surface treatment is usually 10 nm or more, preferably 50 nm or more, and usually 2000 nm or less, preferably 1000 nm or less. If the film thickness is too thick, the light emission characteristics of the phosphor may be impaired. If the film thickness is too thin, the surface coating may be incomplete and the moisture resistance and dispersibility may not be improved.

  The surface treatment method is not particularly limited, and examples thereof include a coating treatment method using a metal oxide (silicon oxide) as described below.

  The phosphor of the present invention is mixed in an alcohol such as ethanol and stirred, and further an alkaline aqueous solution such as ammonia water is mixed and stirred. Next, a hydrolyzable alkyl silicate such as tetraethylorthosilicate is mixed and stirred. The obtained solution is allowed to stand for 3 to 60 minutes, and then the supernatant containing silicon oxide particles that have not adhered to the phosphor surface is removed with a dropper or the like. Subsequently, after mixing alcohol, stirring, standing, and removing the supernatant several times, a surface-treated phosphor is obtained through a vacuum drying step at 120 ° C. to 150 ° C. for 10 minutes to 5 hours, for example, 2 hours.

  Other methods for surface treatment of the phosphor include, for example, a method in which spherical silicon oxide fine powder is adhered to the phosphor (JP-A-2-209998, JP-A-2-233794), and a phosphor-based silicon compound. A method of attaching a film (Japanese Patent Laid-Open No. 3-231987), a method of coating the surface of phosphor fine particles with polymer fine particles (Japanese Patent Laid-Open No. 6-314593), a phosphor with an organic material, an inorganic material, a glass material, etc. A coating method (Japanese Patent Laid-Open No. 2002-223008), a method of coating a phosphor surface by a chemical vapor reaction method (Japanese Patent Laid-Open No. 2005-82788), and a method of attaching metal compound particles (Japanese Patent Laid-Open No. 2006-2006) No. 28458) can be used.

[1-4. Use of phosphor]
The phosphor of the present invention can be used for any application that uses the phosphor. In particular, taking advantage of the fact that it can be excited by blue light or near-ultraviolet light, various light emitting devices (see “ The light-emitting device of the invention ") can be suitably used. By adjusting the types and usage ratios of the phosphors to be combined, light emitting devices having various emission colors can be manufactured. In particular, since the phosphor of the present invention is a green phosphor, a white light emitting device is manufactured by combining an excitation light source that emits blue light and a phosphor that emits orange or red fluorescence (orange or red phosphor). be able to. The emission color in this case can be changed to a desired emission color by adjusting the emission wavelength of the phosphor of the present invention or the combined orange or red phosphor. For example, so-called pseudo white (for example, blue LED and It is also possible to obtain an emission spectrum similar to the emission spectrum of the light emitting device combining the yellow phosphor. Furthermore, combining this white light-emitting device with a phosphor that emits red fluorescence (red phosphor) realizes a light-emitting device that excels in red color rendering and a light-emitting device that emits light bulb color (warm white). can do. A white light emitting device can also be manufactured by combining the phosphor of the present invention with a phosphor emitting blue fluorescence (blue phosphor) and a red phosphor in an excitation light source that emits near ultraviolet light.

  The emission color of the light emitting device is not limited to white, and if necessary, a yellow phosphor (phosphor that emits yellow fluorescence), a blue phosphor, an orange to red phosphor, or another type of green phosphor may be combined. Thus, a light-emitting device that emits light of any color can be manufactured by adjusting the type and usage ratio of the phosphor. The light-emitting device thus obtained can be used as a light-emitting portion (particularly a liquid crystal backlight) or an illumination device of an image display device. In particular, the phosphor of the present invention has a wide color reproduction range when used as an image display device.

[2. Phosphor-containing composition]
The phosphor of the present invention can be used by mixing with a liquid medium. In particular, when the phosphor of the present invention is used for applications such as a light emitting device, it is preferably used in a form dispersed in a liquid medium. The phosphor of the present invention dispersed in a liquid medium will be referred to as “the phosphor-containing composition of the present invention” as appropriate.

[2-1. Phosphor]
There is no restriction | limiting in the kind of fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention, It can select arbitrarily from what was mentioned above. Moreover, the fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, the phosphor-containing composition of the present invention may contain a phosphor other than the phosphor of the present invention as long as the effects of the present invention are not significantly impaired.

[2-2. Liquid medium]
The liquid medium used in the phosphor-containing composition of the present invention is not particularly limited as long as the performance of the phosphor is not impaired within the intended range. For example, any inorganic material and / or organic material may be used as long as it exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. it can.

  As the inorganic material, for example, a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof, an inorganic material (for example, a siloxane bond) Inorganic materials having

  Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specifically, for example, methacrylic resin such as polymethylmethacrylate; styrene resin such as polystyrene and styrene-acrylonitrile copolymer; polycarbonate resin; polyester resin; phenoxy resin; butyral resin; polyvinyl alcohol; Cellulose resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins.

  Among these, when using a phosphor for a high-power light-emitting device such as illumination, it is preferable to use a silicon-containing compound for the purpose of heat resistance and light resistance.

  The silicon-containing compound refers to a compound having a silicon atom in the molecule, for example, an organic material (silicone material) such as polyorganosiloxane, an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, and borosilicate. And glass materials such as phosphosilicate and alkali silicate. Among these, silicone materials are preferable from the viewpoint of ease of handling.

The silicone material generally refers to an organic polymer having a siloxane bond as a main chain, and examples thereof include a compound represented by the following formula (i) and / or a mixture thereof.

In the above formula (i), R ¹ to R ⁶ may be the same or different and are selected from the group consisting of an organic functional group, a hydroxyl group and a hydrogen atom.
In the above formula (i), M, D, T, and Q are numbers that are 0 or more and less than 1, respectively, and that satisfy M + D + T + Q = 1.

  When used for sealing a semiconductor light emitting device, the silicone material can be used after being sealed with a liquid silicone material and then cured by heat or light.

  When silicone materials are classified according to the mechanism of curing, silicone materials such as an addition polymerization curing type, a condensation polymerization curing type, an ultraviolet curing type, and a peroxide vulcanization type can be generally cited. Among these, addition polymerization curing type (addition type silicone resin), condensation curing type (condensation type silicone resin), and ultraviolet curing type are preferable. Hereinafter, the addition type silicone material and the condensation type silicone material will be described.

  The addition-type silicone material refers to a material in which a polyorganosiloxane chain is crosslinked by an organic addition bond. A typical example is a compound having a Si—C—C—Si bond at a crosslinking point obtained by reacting vinylsilane and hydrosilane in the presence of an addition catalyst such as a Pt catalyst. As these, commercially available products can be used. Specific examples of addition polymerization curing type trade names include “LPS-1400”, “LPS-2410”, and “LPS-3400” manufactured by Shin-Etsu Chemical Co., Ltd.

On the other hand, examples of the condensation type silicone material include a compound having a Si—O—Si bond obtained by hydrolysis and polycondensation of an alkylalkoxysilane at a crosslinking point.
Specific examples include polycondensates obtained by hydrolysis and polycondensation of compounds represented by the following general formula (ii) and / or (iii) and / or oligomers thereof.

^{_{M m + X n Y 1 mn}} (ii)
(In formula (ii), M represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. M represents one or more integers representing the valence of M, and n represents one or more integers representing the number of X groups, provided that m ≧ n.

M ^{s +} X _t Y ¹ _st-1 (iii)
(In formula (iii), M represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. Y ² represents a u-valent organic group, s represents an integer of 1 or more representing the valence of M, t represents an integer of 1 or more and s−1 or less, and u represents 2 or more. Represents an integer.)

  Further, the condensation type silicone material may contain a curing catalyst. As this curing catalyst, for example, a metal chelate compound or the like can be suitably used. The metal chelate compound preferably contains one or more of Ti, Ta, and Zr, and more preferably contains Zr. In addition, only 1 type may be used for a curing catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

  As such a condensation type silicone material, for example, semiconductor light emitting device members described in Japanese Patent Application Nos. 2006-47274 to 47277 and Japanese Patent Application No. 2006-176468 are suitable.

Of the condensed silicone materials, particularly preferred materials will be described below.
Silicone materials generally have a problem of poor adhesion to semiconductor light emitting elements, substrates on which elements are arranged, packages, and the like, but as silicone materials having high adhesion, the following features [1] to A condensation type silicone material having one or more of [3] is preferred.

[1] The silicon content is 20% by weight or more.
[2] The solid Si-nuclear magnetic resonance (NMR) spectrum measured by the method described in detail later has at least one peak derived from Si in the following (a) and / or (b).
(A) A peak whose peak top position is in a region where the chemical shift is −40 ppm or more and 0 ppm or less with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 3.0 ppm or less.
(B) A peak whose peak top position is in a region where the chemical shift is −80 ppm or more and less than −40 ppm with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 5.0 ppm or less.
[3] The silanol content is 0.1% by weight or more and 10% by weight or less.

In the present invention, among the above features [1] to [3], a silicone material having the feature [1] is preferable, a silicone material having the above features [1] and [2] is more preferable, Particularly preferred are silicone materials having all the features [1] to [3].
Hereinafter, the above features [1] to [3] will be described.

<2-2-1. Feature [1] (silicon content)>
The basic skeleton of a conventional silicone material is an organic resin such as an epoxy resin having a carbon-carbon and carbon-oxygen bond as the basic skeleton, whereas the basic skeleton of the silicone material of the present invention is glass (silicate). It is the same inorganic siloxane bond as glass). As is apparent from the chemical bond comparison table shown in Table 1 below, this siloxane bond has the following characteristics excellent as a silicone material.

(I) Since the binding energy is large and thermal decomposition and photolysis are difficult, light resistance is good.
(II) It is slightly polarized electrically.
(III) The degree of freedom of the chain structure is large, a structure with high flexibility is possible, and the chain structure can freely rotate around the center of the siloxane chain.
(IV) The degree of oxidation is large and no further oxidation occurs.
(V) Rich in electrical insulation.

  Because of these characteristics, silicone-based silicone materials that are formed with a skeleton in which siloxane bonds are three-dimensionally bonded with a high degree of crosslinking are close to inorganic materials such as glass or rock, and have a high heat resistance and light resistance. Can be understood. In particular, a silicone-based material having a methyl group as a substituent has no absorption in the ultraviolet region, so that photolysis hardly occurs and has excellent light resistance.

The silicon content of the silicone material suitable for the present invention is usually 20% by weight or more, preferably 25% by weight or more, and more preferably 30% by weight or more. On the other hand, the upper limit is usually in the range of 47% by weight or less because the silicon content of the glass composed solely of SiO ₂ is 47% by weight.

  Note that the silicon content of the silicone-based material is calculated based on the results obtained by performing inductively coupled plasma spectroscopy (hereinafter abbreviated as “ICP” as appropriate), for example, using the following method. be able to.

{Measurement of silicon content}
Silicone material is baked in a platinum crucible in the air at 450 ° C. for 1 hour, then at 750 ° C. for 1 hour, and at 950 ° C. for 1.5 hours to remove the carbon component, and then a small amount of residue is obtained. Add more than 10 times the amount of sodium carbonate and heat with a burner to melt, cool this, add demineralized water, and adjust the pH to neutral with hydrochloric acid to a few ppm as silicon. ICP analysis is performed.

<2-2-2. Feature [2] (Solid Si-NMR Spectrum)>
When a solid Si-NMR spectrum of a silicone-based material suitable for the present invention is measured, at least one peak in the peak region of (a) and / or (b) derived from a silicon atom to which a carbon atom of an organic group is directly bonded, Preferably, a plurality of peaks are observed.

When arranged for each chemical shift, in the silicone-based material suitable for the present invention, the half width of the peak described in (a) is generally less than the peak described in (b) described later because molecular motion is less restricted. It is smaller than the case, usually in the range of 3.0 ppm or less, preferably 2.0 ppm or less, and usually 0.3 ppm or more.
On the other hand, the full width at half maximum of the peak described in (b) is usually 5.0 ppm or less, preferably 4.0 ppm or less, and usually 0.3 ppm or more, preferably 0.4 ppm or more.

  If the half-value width of the peak observed in the chemical shift region is too large, the molecular motion is constrained and the strain becomes large, cracks are likely to occur, and the member may be inferior in heat resistance and weather resistance. For example, in the case where a large amount of tetrafunctional silane is used, or in the state where rapid drying is performed in the drying process and a large internal stress is stored, the full width at half maximum is larger than the above range.

  In addition, if the half width of the peak is too small, Si atoms in the environment will not be involved in siloxane crosslinking, and heat resistance is higher than that of substances formed mainly from siloxane bonds, such as cases where trifunctional silane remains in an uncrosslinked state. -It may be a member inferior in weather resistance.

  However, in a silicone material containing a small amount of Si component in a large amount of organic component, good heat resistance / light resistance and coating performance can be obtained even if the peak of the above-mentioned half width range is observed at -80 ppm or more. There may not be.

  The chemical shift value of the silicone material suitable for the present invention can be calculated based on the results of solid Si-NMR measurement using the following method, for example. In addition, analysis of measurement data (half-width or silanol amount analysis) is performed by a method of dividing and extracting each peak by, for example, waveform separation analysis using a Gaussian function or a Lorentz function.

{Solid Si-NMR spectrum measurement and silanol content calculation}
When performing a solid Si-NMR spectrum about a silicone type material, a solid Si-NMR spectrum measurement and waveform separation analysis are performed on condition of the following. Further, from the obtained waveform data, the half width of each peak is determined for the silicone material. Also, from the ratio of the peak area derived from silanol to the total peak area, the ratio (%) of silicon atoms that are silanols in all silicon atoms is obtained, and the silanol content is determined by comparing with the silicon content analyzed separately. Ask.

{Device conditions}
Apparatus: Chemmagnetics Infinity CMX-400 Nuclear magnetic resonance spectrometer 29Si resonance frequency: 79.436 MHz
Probe: 7.5 mmφ CP / MAS probe Measurement temperature: room temperature Sample rotation speed: 4 kHz
Measurement method: Single pulse method 1H decoupling frequency: 50 kHz
29Si flip angle: 90 ° 29Si90 ° pulse width: 5.0μs
Repeat time: 600s
Integration count: 128 Observation width: 30 kHz
Broadening factor: 20Hz
Reference sample: Tetramethoxysilane

  For silicone-based materials, 512 points are taken as measurement data, zero-filled to 8192 points, and Fourier transformed.

{Waveform separation analysis method}
For each peak of the spectrum after Fourier transform, optimization calculation is performed by a non-linear least square method with the center position, height, and half width of the peak shape created by Lorentz waveform and Gaussian waveform or a mixture of both as variable parameters.
In addition, identification of a peak is AIChE Journal, 44 (5), p. Refer to 1141, 1998, etc.

<2-2-3. Feature [3] (Silanol Content)>
The silicone material suitable for the present invention has a silanol content of usually 0.1% by weight or more, preferably 0.3% by weight or more, and usually 10% by weight or less, preferably 8% by weight or less, more preferably The range is 5% by weight or less. By reducing the silanol content, the silanol-based material has excellent performance with little change over time, excellent long-term performance stability, and low moisture absorption and moisture permeability. However, since a member containing no silanol is inferior in adhesion, there exists an optimum range for the silanol content as described above.

  The silanol content of the silicone material is, for example, <2-2-2. Characteristic [2] (Solid Si-NMR spectrum)> The solid Si-NMR spectrum was measured using the method described in the section {Measurement of solid Si-NMR spectrum and calculation of silanol content}. It can be calculated by obtaining the ratio (%) of silicon atoms that are silanols in all silicon atoms from the ratio of the peak area derived from and comparing with the silicon content analyzed separately.

  In addition, since the silicone-based material suitable for the present invention contains an appropriate amount of silanol, the silanol usually bonds with hydrogen at the polar portion present on the device surface, thereby exhibiting adhesion. Examples of the polar part include a hydroxyl group and a metalloxane-bonded oxygen.

  In addition, the silicone material suitable for the present invention is usually heated in the presence of an appropriate catalyst to form a covalent bond by dehydration condensation with the hydroxyl group on the device surface, thereby exhibiting stronger adhesion. can do.

  On the other hand, if there is too much silanol, the inside of the system will thicken and it will be difficult to apply, or it will become more active and solidify before the light-boiling components volatilize by heating, leading to increased foaming and internal stress. It may occur and induce cracks.

[2-3. Content of liquid medium]
The content of the liquid medium is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 50% by weight or more, preferably 75% by weight or more, based on the entire phosphor-containing composition of the present invention. It is 99 weight% or less, Preferably it is 95 weight% or less. When the amount of the liquid medium is large, no particular problem occurs. However, in order to obtain a desired chromaticity coordinate, color rendering index, luminous efficiency, etc. in the case of a semiconductor light emitting device, it is usually at a blending ratio as described above. It is desirable to use a liquid medium. On the other hand, if there is too little liquid medium, there is a possibility that it will be difficult to handle due to lack of fluidity.

  The liquid medium mainly serves as a binder in the phosphor-containing composition of the present invention. Only one type of liquid medium may be used, but two or more types may be used in any combination and ratio. For example, when a silicon-containing compound is used for the purpose of heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the silicon-containing compound is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less based on the total amount of the liquid medium as the binder.

[2-4. Other ingredients]
The phosphor-containing composition of the present invention may contain other components in addition to the phosphor and the liquid medium as long as the effects of the present invention are not significantly impaired. Moreover, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

[3. Light emitting device]
The light-emitting device of the present invention (hereinafter referred to as “light-emitting device” as appropriate) includes a first light-emitting body (excitation light source), and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. A light-emitting device having the above-described [1. One or more phosphors of the present invention described in the section of “phosphor” are contained as the first phosphor.

  As the phosphor of the present invention, a phosphor that emits green region fluorescence under irradiation of light from an excitation light source (hereinafter sometimes referred to as “the green phosphor of the present invention”) is usually used. Specifically, the green phosphor of the present invention preferably has an emission peak in the range of 510 nm to 542 nm. Only one kind of the green phosphor of the present invention may be used, or two or more kinds may be used in any combination and ratio.

  By using the green phosphor of the present invention, the light emitting device of the present invention exhibits high emission efficiency with respect to an excitation light source (first light emitter) having light emission from the near ultraviolet to the blue region, When used in a white light-emitting device such as a light source for liquid crystal display, the light-emitting device is excellent in that the color reproduction range of the display is widened.

  In addition, as a measuring method of the emission spectrum of a fluorescent substance, a chromaticity coordinate value, and each other physical-property value, said [1. A method similar to that described in the section “Phosphor” can be used.

  Moreover, as a preferable specific example of the green phosphor of the present invention used in the light emitting device of the present invention, [1. Examples thereof include the phosphor of the present invention described in the “Phosphor” column and the phosphors used in the respective Examples in the “Example” column described later.

  The light-emitting device of the present invention has a first light emitter (excitation light source), and at least the phosphor of the present invention is used as the second light emitter. It is possible to arbitrarily adopt the apparatus configuration. A specific example of the device configuration will be described later.

  As the emission peak in the green region in the emission spectrum of the light emitting device of the present invention, one having an emission peak in the wavelength range of 515 nm to 535 nm is preferable.

  Note that the emission spectrum of the light emitting device is measured by energizing 20 mA with a color / illuminance measurement software and USB2000 series spectroscope (integral sphere specification) manufactured by Ocean Optics in a room maintained at a temperature of 25 ± 1 ° C. Can be done. Chromaticity values (x, y, z) can be calculated as chromaticity coordinates in the XYZ color system defined by JIS Z8701 from data in the wavelength region of 380 nm to 780 nm of the emission spectrum. In this case, the relational expression x + y + z = 1 holds. In the present specification, the XYZ color system may be referred to as an XY color system, and is usually expressed as (x, y).

  The light-emitting device of the present invention is also characterized by a high NTSC ratio, particularly when a white light-emitting device is used. Specifically, the NTSC ratio (%) of the light emitting device of the present invention is usually 70 or more, preferably 72 or more, more preferably 74 or more. The NTSC ratio is preferably as high as possible, but theoretically it is 150 or less.

In addition, the measuring method of NTSC ratio is as follows.
In the NTSC system, which is the standard of Japanese color TV, the standard R, G, B chromaticity points are defined as follows by the point (x, y) on the CIE chromaticity coordinates.
R (0.67, 0.33), G (0.21, 0.71), B (0.14, 0.08)

  When the area of a triangle formed by the three RGB points is defined as 100, the area of the triangle formed by the R, G, and B of the display to be obtained, specifically, the monochrome RGB is emitted by the display to be obtained, and the chromaticity ( x, y) is measured, and a value obtained by dividing the area of the triangle obtained by plotting on the CIE chromaticity diagram by the area of the standard triangle of NTSC is defined as NTSC ratio (%).

  The luminous efficiency is obtained by obtaining the total luminous flux from the result of the emission spectrum measurement using the light emitting device as described above, and dividing the lumen (lm) value by the power consumption (W). The power consumption is obtained by measuring a voltage using a True RMS Multimeters Model 187 & 189 manufactured by Fluke in a state in which 20 mA is energized, and obtaining the product of the current value and the voltage value.

  Among the light emitting devices of the present invention, in particular, the white light emitting device uses an excitation light source as described later as the first light emitter, and in addition to the green phosphor as described above, A phosphor that emits fluorescence (hereinafter referred to as “red phosphor” as appropriate), a phosphor that emits blue fluorescence (hereinafter referred to as “blue phosphor” as appropriate), and a phosphor that emits yellow fluorescence (hereinafter referred to as “yellow fluorescence” as appropriate). It is obtained by using known phosphors such as “body”) in any combination and adopting a known device configuration.

  Here, the white color of the white light emitting device means all of (yellowish) white, (greenish) white, (blueish) white, (purple) white and white defined by JIS Z 8701 Of these, white is preferred.

[3-1. Configuration of Light Emitting Device (Light Emitter)]
(First luminous body)
The 1st light-emitting body in the light-emitting device of this invention light-emits the light which excites the 2nd light-emitting body mentioned later.

  The light emission wavelength of the first light emitter is not particularly limited as long as it overlaps with the absorption wavelength of the second light emitter described later, and a light emitter having a wide light emission wavelength region can be used. Usually, an illuminant having an emission wavelength from the ultraviolet region to the blue region is used, and it is particularly preferable to use an illuminant having an emission wavelength from the near ultraviolet region to the blue region.

  As a specific numerical value of the emission wavelength of the first luminous body, 200 nm or more is usually desirable. Among these, when using near-ultraviolet light as excitation light, it is desirable to use a light emitter having a peak emission wavelength of usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 420 nm or less. When blue light is used as excitation light, it is desirable to use an illuminant having a peak emission wavelength of usually 420 nm or more, preferably 430 nm or more, and usually 500 nm or less, preferably 480 nm or less. Both are from the viewpoint of color purity of the light emitting device.

  As the first light emitter, a semiconductor light emitting element is generally used, and specifically, a light emitting LED, a semiconductor laser diode (hereinafter abbreviated as “LD” as appropriate), or the like can be used. In addition, as a light-emitting body which can be used as a 1st light-emitting body, an organic electroluminescent light emitting element, an inorganic electroluminescent light emitting element, etc. are mentioned, for example. However, what can be used as a 1st light-emitting body is not restricted to what is illustrated by this specification.

Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. GaN-based LEDs and LDs preferably have an Al _x Ga _y N light emitting layer, a GaN light emitting layer, or an In _x Ga _y N light emitting layer. Among GaN-based LEDs, those having an In _X Ga _Y N light-emitting layer are particularly preferable because of their very high emission intensity. In GaN-based LEDs, a multiple quantum well structure of In _X Ga _Y N layers and GaN layers is preferred. Is particularly preferable because the emission intensity is very strong.

  In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is composed of n-type and p-type Al _x Ga _y N layers, GaN layers, or In _x. Those having a hetero structure sandwiched by Ga _Y N layers or the like are preferable because of high light emission efficiency, and those having a hetero structure having a quantum well structure are more preferable because of high light emission efficiency.
Note that only one first light emitter may be used, or two or more first light emitters may be used in any combination and ratio.

(Second light emitter)
The second light emitter in the light emitting device of the present invention is a light emitter that emits visible light when irradiated with the light from the first light emitter, and the phosphor of the present invention (green) is used as the first phosphor. And a second fluorescent material (a red fluorescent material, a blue fluorescent material, an orange fluorescent material, etc.), which will be described later, appropriately. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing material.

Used for the in the second luminescent material is not particularly limited to the phosphor composition other than the phosphor of the present invention, the crystal _{matrix, Y 2 O 3, YVO 4} , Zn 2 SiO 4, Y 3 Metal oxides typified by Al ₅ O ₁₂ , Sr ₂ SiO ₄ , metal nitrides typified by Sr ₂ Si ₅ N ₈ , phosphates typified by Ca ₅ (PO ₄ ) ₃ Cl, etc. Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, sulfides typified by ZnS, SrS, CaS, etc., oxysulfides typified by Y ₂ O ₂ S, La ₂ O ₂ S, etc. A combination of rare earth metal ions such as Ho, Er, Tm, and Yb, and metal ions such as Ag, Cu, Au, Al, Mn, and Sb as activators or coactivators.

Preferred examples of the crystal matrix include, for example, sulfides such as (Zn, Cd) S, SrGa ₂ S ₄ , SrS, ZnS; oxysulfides such as Y ₂ O ₂ S; (Y, Gd) ₃ Al ₅ O ₁₂ , YAlO ₃ , BaMgAl ₁₀ O ₁₇ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ , (Ba, Sr, Ca) (Mg, Zn, Mn) Al ₁₀ O ₁₇ , BaAl ₁₂ O ₁₉ , CeMgAl Aluminates such as ₁₁ O ₁₉ , (Ba, Sr, Mg) O.Al ₂ O ₃ , BaAl ₂ Si ₂ O ₈ , SrAl ₂ O ₄ , Sr ₄ Al ₁₄ O ₂₅ , Y ₃ Al ₅ O ₁₂ ; Y Silicates such as ₂ SiO ₅ and Zn ₂ SiO ₄ ; Oxides such as SnO ₂ and Y ₂ O ₃ ; Borates such as GdMgB ₅ O ₁₀ and (Y, Gd) BO ₃ ; Ca ₁₀ (PO ₄ ) ₆ ( _{F, Cl) 2, (Sr} , Ca, Ba, Mg) 10 (PO 4) 6 halophosphate of ₂ such as Cl; Sr ₂ P _{2 7,} it may be mentioned (La, Ce) phosphate PO _4, etc. and the like.

  However, the crystal matrix and the activator element or coactivator element are not particularly limited in element composition, and can be partially replaced with elements of the same family, and the obtained phosphor is light in the near ultraviolet to visible region. Any material that absorbs and emits visible light can be used.

  Specifically, the following phosphors can be used, but these are merely examples, and phosphors that can be used in the present invention are not limited to these. In the following examples, as described above, phosphors that differ only in part of the structure are omitted as appropriate.

(First phosphor)
The second light emitter in the light emitting device of the present invention contains at least the above-described phosphor of the present invention as the first phosphor. Any one of the phosphors of the present invention may be used, or two or more may be used in any combination and ratio. In addition to the phosphor of the present invention, a phosphor that emits fluorescence of the same color as the phosphor of the present invention (same color combined phosphor) may be used as the first phosphor. Usually, since the phosphor of the present invention is a green phosphor, another type of green phosphor can be used in combination with the phosphor of the present invention as the first phosphor.

Any green phosphor can be used as long as the effects of the present invention are not significantly impaired.
Specifically, the green phosphor is composed of, for example, fractured particles having a fractured surface, and emits a green region (Mg, Ca, Sr, Ba) with europium represented by Si ₂ O ₂ N ₂ : Eu. Examples include active alkaline earth silicon oxynitride phosphors.

Other green phosphors include Eu-activated aluminate phosphors such as Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, and (Sr, Ba) Al _{2. Si 2 O 8: Eu, (} Ba, Mg) 2 SiO 4: Eu, (Ba, Sr, Ca, Mg) 2 SiO 4: Eu, (Ba, Sr, Ca) 2 (Mg, Zn) Si 2 O 7 : Eu, (Ba, Ca, Sr, Mg) ₉ (Sc, Y, Lu, Gd) ₂ (Si, Ge) ₆ O ₂₄ : Eu-activated silicate phosphor such as Eu, Y ₂ SiO ₅ : Ce, Ce, Tb activated silicate phosphor such as Tb, Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu activated borate phosphate phosphor such as Eu, Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu-activated halo silicate phosphor such as Eu, Zn ₂ SiO _4: Mn-activated silicate phosphors such as _{Mn, CeMgAl 11 O 19: Tb} , ₃ Al ₅ O _12: Tb-activated aluminate phosphors such as _{Tb, Ca 2 Y 8 (SiO} 4) 6 O 2: Tb, La 3 Ga 5 SiO 14: Tb -activated silicate phosphors such as Tb, (Sr, Ba, Ca) Ga ₂ S ₄ : Eu, Tb, Sm activated thiogallate phosphors such as Eu, Tb, Sm, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Y, Ga, Tb, La, Sm, Pr, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce activated silicate phosphor such as Ce, Ce activated oxide phosphor such as CaSc ₂ O ₄ : Ce, Eu activated oxynitride phosphor such as Eu activated β sialon _{, BaMgAl 10 O 17: Eu,} Eu such as Mn, Mn-activated aluminate phosphor, SrAl ₂ O _4: Eu such as Eu Activated aluminate phosphors, (La, Gd, Y) 2 O 2 S: Tb Tsukekatsusan sulfide phosphor such as Tb, LaPO _4: Ce, Ce and Tb such, Tb-activated phosphate phosphor, Sulfide phosphors such as ZnS: Cu, Al, ZnS: Cu, Au, Al, (Y, Ga, Lu, Sc, La) BO ₃ : Ce, Tb, Na ₂ Gd ₂ B ₂ O ₇ : Ce, Tb (Ba, Sr) ₂ (Ca, Mg, Zn) B ₂ O ₆ : Ce, Tb activated borate phosphors such as K, Ce, Tb, Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu, Mn Eu, Mn activated halosilicate phosphors such as (Sr, Ca, Ba) (Al, Ga, In) ₂ S ₄ : Eu activated thioaluminate phosphors and thiogallate phosphors such as Eu, (Ca, Sr) ₈ (Mg, Zn) (SiO ₄ ) ₄ Cl ₂ : Eu, Mn activated halosilicate phosphor such as Eu, Mn, M ₃ S i ₆ O ₉ N ₄ : Eu, M ₃ Si ₆ O ₁₂ N ₂ : Eu (where M represents an alkaline earth metal element). It is also possible to use Eu-activated oxynitride phosphors such as

In addition, as the green phosphor, it is also possible to use a pyridine-phthalimide condensed derivative, a benzoxazinone-based, a quinazolinone-based, a coumarin-based, a quinophthalone-based, a nartaric imide-based fluorescent dye, or an organic phosphor such as a terbium complex. is there.
Any one of the green phosphors exemplified above may be used, or two or more may be used in any combination and ratio.

The emission peak wavelength λ _p (nm) of the first phosphor used in the light emitting device of the present invention is usually larger than 500 nm, especially 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 542 nm or less, Is preferably in the range of 535 nm or less. If this emission peak wavelength λ _p is too short, it tends to be bluish, while if it is too long, it tends to be yellowish, and the characteristics as green light may deteriorate.

  The first phosphor used in the light emitting device of the present invention has an emission peak half width (full width at half maximum, hereinafter abbreviated as “FWHM” as appropriate) in the above-described emission spectrum, usually 10 nm or more. The thickness is preferably 20 nm or more, more preferably 25 nm or more, and usually 85 nm or less, particularly 75 nm or less, and more preferably 70 nm or less. If the full width at half maximum FWHM is too narrow, the emission intensity may decrease, and if it is too wide, the color purity may decrease.

(Second phosphor)
The second light emitter in the light emitting device of the present invention may contain a phosphor (that is, a second phosphor) in addition to the first phosphor described above, depending on the application. This second phosphor is a phosphor having an emission peak wavelength different from that of the first phosphor. Usually, since these second phosphors are used to adjust the color tone of light emitted from the second light emitter, the second phosphor emits fluorescence having a color different from that of the first phosphor. Often phosphors are used. As described above, since a green phosphor is usually used as the first phosphor, examples of the second phosphor include other than green phosphors such as orange to red phosphor, blue phosphor, and yellow phosphor. A phosphor is used.

  The weight median diameter of the second phosphor used in the light emitting device of the present invention is usually in the range of 10 μm or more, especially 12 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur.

(Orange to red phosphor)
When an orange or red phosphor is used as the second phosphor, any orange or red phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the orange to red phosphor is usually in the wavelength range of 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. Is preferred.

Examples of such orange to red phosphors are europium composed of broken particles having a red fracture surface and emitting red region (Mg, Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu. The activated alkaline earth silicon nitride phosphor is composed of growing particles having a substantially spherical shape as a regular crystal growth shape, and emits light in the red region (Y, La, Gd, Lu) ₂ O ₂ S: Eu And europium activated rare earth oxychalcogenide phosphors represented by the formula:

  Furthermore, an oxynitride and / or an acid containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A No. 2004-300247 A phosphor containing a sulfide and containing an oxynitride having an alpha sialon structure in which a part or all of the Al element is substituted with a Ga element can also be used in the present invention. These are phosphors containing oxynitride and / or oxysulfide.

In addition, examples of red phosphors include Eu-activated oxysulfide phosphors such as (La, Y) ₂ O ₂ S: Eu, Y (V, P) O ₄ : Eu, Y ₂ O ₃ : Eu, and the like. Eu-activated oxide phosphors of (Ba, Mg) ₂ SiO ₄ : Eu, Mn, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, Mn-activated silicate phosphors such as Eu and Mn, Eu-activated tungstate phosphors such as LiW ₂ O ₈ : Eu, LiW ₂ O ₈ : Eu, Sm, Eu ₂ W ₂ O ₉ , Eu ₂ W ₂ O ₉ : Nb, Eu ₂ W ₂ O ₉ : Sm Eu-activated sulfide phosphors such as (Ca, Sr) S: Eu, Eu-activated aluminate phosphors such as YAlO ₃ : Eu, Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ : Eu, LiY _{9 (SiO 4) 6 O 2:} Eu, (Sr, Ba, Ca) 3 SiO 5: Eu, Sr 2 BaSiO 5: Eu -activated silicate phosphors such as Eu, _{Y, Gd) 3 Al 5 O} 12: Ce, (Tb, Gd) 3 Al 5 O 12: Ce -activated aluminate phosphor such as Ce, (Mg, Ca, Sr , Ba) 2 Si 5 (N, Eu-activated oxides such as O) ₈ : Eu, (Mg, Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Eu , Nitride or oxynitride phosphor, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Ce activated oxide such as Ce, nitride or oxynitride phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn-activated halophosphate phosphor such as Eu, Mn, Ba ₃ MgSi ₂ O ₈ : Eu, Mn, (Ba, Sr, Ca, Mg) ₃ (Zn, Mg) Si ₂ O ₈ : Eu, Mn activated silicate phosphor such as Eu, Mn, 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn Mn-activated germanate phosphor such as Eu-activated α-sialon phosphor such as Eu-activated α-sialon, (Gd, Y, Lu, La) ₂ O ₃ : Eu, Bi-activated Eu, Bi, etc. Oxide phosphor, (Gd, Y, Lu, La) ₂ O ₂ S: Eu, Bi activated oxysulfide phosphor such as Eu, Bi, (Gd, Y, Lu, La) VO ₄ : Eu, Bi Eu, Bi activated vanadate phosphors such as SrY ₂ S ₄ : Eu, Ce activated sulfide phosphors such as Eu, Ce, Ce activated sulfide phosphors such as CaLa ₂ S ₄ : Ce, ( Ba, Sr, Ca) MgP ₂ O ₇ : Eu, Mn, (Sr, Ca, Ba, Mg, Zn) ₂ P ₂ O ₇ : Eu, Mn activated phosphate phosphor such as Eu, Mn, (Y _{, Lu) 2 WO 6: Eu} , Eu such as Mo, Mo-activated tungstate phosphor, (Ba, Sr, Ca) x Si y N z: Eu, Ce However, x, y, z are an integer of 1 or more. Eu, Ce-activated nitride phosphors such as (Ca, Sr, Ba, Mg) ₁₀ (PO ₄ ) ₆ (F, Cl, Br, OH): Eu, Mn-activated halophosphoric acid such as Eu, Mn Ce phosphors such as salt phosphors, ((Y, Lu, Gd, Tb) _1-xy Sc _x Ce _y ) ₂ (Ca, Mg) _1-r (Mg, Zn) _{2 + r} Si _zq Ge _q O _{12 + δ} It is also possible to use an activated silicate phosphor or the like.

  Examples of red phosphors include β-diketonates, β-diketones, aromatic carboxylic acids, red organic phosphors composed of rare earth element ion complexes having an anion such as Bronsted acid as a ligand, and perylene pigments (for example, Dibenzo {[f, f ′]-4,4 ′, 7,7′-tetraphenyl} diindeno [1,2,3-cd: 1 ′, 2 ′, 3′-lm] perylene), anthraquinone pigment, Lake pigments, azo pigments, quinacridone pigments, anthracene pigments, isoindoline pigments, isoindolinone pigments, phthalocyanine pigments, triphenylmethane basic dyes, indanthrone pigments, indophenol pigments, It is also possible to use a cyanine pigment or a dioxazine pigment.

Among these, as red phosphors, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr , Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, It is preferable to contain (La, Y) ₂ O ₂ S: Eu or Eu complex, more preferably (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si. (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO _{5: Eu, (Ca, Sr} ) S: Eu or _{(La, Y) 2 O 2} S: Eu or Eu (dibenzoylmethane) ₃ · 1, Preferably comprises a β- diketone Eu complex or carboxylic acid type Eu complex such as 10-phenanthroline complex, (Ca, Sr, Ba) 2 Si 5 (N, O) 8: Eu, (Sr, Ca) AlSiN 3 : Eu or (La, Y) ₂ O ₂ S: Eu is particularly preferred.

Of the above examples, (Sr, Ba) ₃ SiO ₅ : Eu is preferable as the orange phosphor.

(Blue phosphor)
When a blue phosphor is used as the second phosphor, any blue phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the blue phosphor is usually 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, preferably 480 nm or less, more preferably 470 nm or less, and further preferably 460 nm or less. It is preferable to be in the wavelength range.

As such a blue phosphor, europium represented by (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu which is composed of growing particles having a substantially hexagonal shape as a regular crystal growth shape and emits light in a blue region. The activated barium magnesium aluminate phosphor is composed of growing particles having a substantially spherical shape as a regular crystal growth shape, and emits light in the blue region (Mg, Ca, Sr, Ba) ₅ (PO ₄ ) ₃ (Cl , F): Europium-activated calcium halophosphate phosphor represented by Eu, composed of grown particles having a substantially cubic shape as a regular crystal growth shape, and emits light in a blue region (Ca, Sr, Ba) ₂ B ₅ O ₉ Cl: europium-activated alkaline earth represented by Eu aluminate-based phosphor is composed of fractured particles having a fractured surface Performing light emission in the blue-green region (Sr, Ca, Ba) Al 2 O 4: Eu or _{(Sr, Ca, Ba) 4} Al 14 O 25: europium-activated alkaline earth aluminate phosphor such as represented by Eu is Can be mentioned.

In addition, as the blue phosphor, Sn-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Sn, (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Tb, Sm, BaAl ₈ O ₁₃ : Eu attached Active aluminate phosphor, Ce-activated thiogallate phosphor such as SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce, Eu, Mn such as (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn Active aluminate phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba, Sr, Ca) ₅ (PO ₄ ) ₃ (Cl, F, Br, OH): Eu, Mn, Eu-activated halophosphate phosphors such as Sb, BaAl ₂ Si _{2 8: Eu, (Sr, Ba} ) 3 MgSi 2 O 8: Eu -activated silicate phosphors such as _{Eu, Sr 2 P 2 O 7} : Eu -activated phosphate phosphor such as Eu, ZnS: Ag, ZnS : Sulfide phosphors such as Ag and Al, Y ₂ SiO ₅ : Ce activated silicate phosphors such as Ce, Tungsten phosphors such as CaWO ₄ , (Ba, Sr, Ca) BPO ₅ : Eu, Mn _{, (Sr, Ca) 10 (} PO 4) 6 · nB 2 O 3: Eu, 2SrO · 0.84P 2 O 5 · 0.16B 2 O 3: Eu such as Eu, Mn-activated borate phosphate phosphors Eu-activated halosilicate phosphors such as Sr ₂ Si ₃ O ₈ .2SrCl ₂ : Eu, Eu-activated oxynitride phosphors such as SrSi ₉ Al ₁₉ ON ₃₁ : Eu, EuSi ₉ Al ₁₉ ON _31, etc. It is also possible to use it.

  In addition, as the blue phosphor, for example, naphthalic acid imide-based, benzoxazole-based, styryl-based, coumarin-based, pyrarizone-based, triazole-based compound fluorescent dyes, thulium complexes and other organic phosphors can be used. .

Among the above examples, as the blue phosphor, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu or It is preferable to contain (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu, and (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ ( Cl, F) ₂ : Eu or (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu is more preferable, and BaMgAl ₁₀ O ₁₇ : Eu, Sr ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : More preferably, Eu or Ba ₃ MgSi ₂ O ₈ : Eu is included. Of these, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu or (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu is particularly preferred for illumination and display applications.

(Yellow phosphor)
When a yellow phosphor is used as the second phosphor, any blue phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the yellow phosphor is usually in the wavelength range of 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. Is preferred.

Examples of such yellow phosphors include various oxide-based, nitride-based, oxynitride-based, sulfide-based, and oxysulfide-based phosphors.
In particular, RE ₃ M ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, and Sm, and M represents Al, Ga, and Sc. And M ^a ₃ M ^b ₂ ^Mc ₃ O ₁₂ : Ce (where M ^a is a divalent metal element and M ^b is a trivalent metal element) , M ^c represents a tetravalent metal element.) Garnet-based phosphor having a garnet structure represented by AE ₂ M ^d O ₄ : Eu (where AE is Ba, Sr, Ca, Mg, and And at least one element selected from the group consisting of Zn, M ^d represents Si and / or Ge), etc., and oxygen of constituent elements of the phosphors of these systems Oxynitride phosphor, part of which is replaced with nitrogen, AEAlS Ce such as nitride phosphors having a CaAlSiN ₃ structure such as iN ₃ : Ce (wherein AE represents at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Zn). And the phosphor activated in step (b).

Other examples of yellow phosphors include sulfide-based fluorescence such as CaGa ₂ S ₄ : Eu, (Ca, Sr) Ga ₂ S ₄ : Eu, (Ca, Sr) (Ga, Al) ₂ S ₄ : Eu. It is also possible to use a phosphor activated by Eu, such as an oxynitride phosphor having a SiAlON structure such as Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Eu.

  Examples of yellow phosphors include brilliant sulfoflavine FF (Color Index Number 56205), basic yellow HG (Color Index Number 46040), eosine (Color Index Number 45e 380a) Etc. can also be used.

(Combination of second phosphors)
As the second phosphor, only one kind of phosphor may be used, or two or more kinds of phosphors may be used in any combination and ratio. Further, the ratio between the first phosphor and the second phosphor is also arbitrary as long as the effects of the present invention are not significantly impaired. Therefore, the amount of the second phosphor used, the combination of phosphors used as the second phosphor, and the ratio thereof may be arbitrarily set according to the use of the light emitting device.

  In the light emitting device of the present invention, the presence / absence and type of the second phosphor (orange to red phosphor, blue phosphor, etc.) described above may be appropriately selected according to the use of the light emitting device. For example, when the light emitting device of the present invention is configured as a green light emitting device, only the first phosphor (green phosphor) may be used, and the use of the second phosphor is usually unnecessary. .

  On the other hand, when the light emitting device of the present invention is configured as a white light emitting device, the first light emitter, the first phosphor (green phosphor), and the first phosphor so as to obtain desired white light. What is necessary is just to combine 2 fluorescent substance appropriately. Specifically, examples of preferable combinations of the first light emitter, the first phosphor, and the second phosphor in the case where the light emitting device of the present invention is configured as a white light emitting device include the following: (I) to (iii) are included.

(I) A blue phosphor (such as a blue LED) is used as the first phosphor, a green phosphor (such as the phosphor of the present invention) is used as the first phosphor, and red fluorescence is used as the second phosphor. Use the body. In this case, the red phosphor is preferably one or more red phosphors selected from the group consisting of (Sr, Ca) AlSiN ₃ : Eu.

(Ii) A near ultraviolet light emitter (near ultraviolet LED or the like) is used as the first light emitter, a green phosphor (such as the phosphor of the present invention) is used as the first phosphor, and the second phosphor is used as the second phosphor. A blue phosphor and a red phosphor are used in combination. In this case, the blue phosphor is selected from the group consisting of (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu and (Mg, Ca, Sr, Ba) ₅ (PO ₄ ) ₃ (Cl, F): Eu. One or more blue phosphors are preferred. The red phosphor is preferably one or two or more red phosphors selected from the group consisting of (Sr, Ca) AlSiN ₃ : Eu and La ₂ O ₂ S: Eu. Among them, it is preferable to use a near ultraviolet LED, the phosphor of the present invention, BaMgAl ₁₀ O ₁₇ : Eu as a blue phosphor, and (Sr, Ca) AlSiN ₃ : Eu as a red phosphor.

(Iii) A blue phosphor (such as a blue LED) is used as the first phosphor, a green phosphor (such as the phosphor of the present invention) is used as the first phosphor, and orange fluorescence is used as the second phosphor. Use the body. In this case, the orange phosphor preferably has an emission peak wavelength of 580 nm or more and 620 nm or less, and (Sr, Ba) ₃ SiO ₅ : Eu is particularly preferable.

  In addition, the phosphor of the present invention is mixed with other phosphors (here, mixing does not necessarily mean that the phosphors need to be mixed with each other, but means that different types of phosphors are combined). ) Can be used. In particular, when phosphors are mixed in the combination described above, a preferable phosphor mixture is obtained. In addition, there is no restriction | limiting in particular in the kind and the ratio of the fluorescent substance to mix.

  Moreover, when manufacturing the various phosphors described above, an imide compound and / or an amide compound containing one or more elements (for example, alkaline earth metal elements) constituting the phosphor are used as raw materials. You can also.

(Sealing material)
In the light emitting device of the present invention, the first and / or second phosphors are usually used by being dispersed in a liquid medium that is a sealing material.
Examples of the liquid medium include [2. Examples thereof are the same as those described in the section “Fluorescent substance-containing composition”.

  The liquid medium can contain a metal element that can be a metal oxide having a high refractive index in order to adjust the refractive index of the sealing member. Examples of metal elements that give a metal oxide having a high refractive index include Si, Al, Zr, Ti, Y, Nb, and B. Only 1 type of these metal elements may be used, and 2 or more types may be used together by arbitrary combinations and a ratio.

The presence form of such a metal element is not particularly limited as long as the transparency of the sealing member is not impaired. For example, even if a uniform glass layer is formed as a metalloxane bond, the metal element is present in a particulate form in the sealing member. It may be. When present in the form of particles, the structure inside the particles may be either amorphous or crystalline, but is preferably a crystalline structure in order to provide a high refractive index. Further, the particle diameter is usually not more than the emission wavelength of the semiconductor light emitting device, preferably not more than 100 nm, more preferably not more than 50 nm, particularly preferably not more than 30 nm so as not to impair the transparency of the sealing member. For example, by mixing particles of silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, niobium oxide, etc. with a silicone-based material, the metal element can be present in the sealing member in the form of particles. .
The liquid medium may further contain known additives such as a diffusing agent, a filler, a viscosity modifier, and an ultraviolet absorber.

[3-2. Configuration of light emitting device (others)]
The light-emitting device of the present invention is not particularly limited as long as it includes the first light-emitting body and the second light-emitting body described above. Usually, the first light-emitting body is formed on an appropriate frame. And a second light emitter. At this time, the second light emitter is excited by the light emission of the first light emitter (that is, the first and second phosphors are excited) to emit light, and the first light emitter emits light. And / or it arrange | positions so that light emission of a 2nd light-emitting body may be taken out outside. In this case, the first phosphor and the second phosphor are not necessarily mixed in the same layer. For example, the second phosphor is contained on the layer containing the first phosphor. For example, the phosphor may be contained in a separate layer for each color development of the phosphor, such as by laminating layers.

  In the light emitting device of the present invention, members other than the above-described excitation light source (first light emitter), phosphor (second light emitter), and frame may be used. Examples thereof include the aforementioned sealing materials. In addition to the purpose of dispersing the phosphor (second light emitter) in the light emitting device, the sealing material is provided between the excitation light source (first light emitter), the phosphor (second light emitter), and the frame. It can be used for the purpose of bonding.

[3-3. Embodiment of Light Emitting Device]
Hereinafter, the light-emitting device of the present invention will be described in more detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and does not depart from the gist of the present invention. It can be implemented with arbitrary modifications.

  FIG. 1 is a schematic perspective view showing a positional relationship between a first light emitter serving as an excitation light source and a second light emitter configured as a phosphor containing portion having a phosphor in an example of the light emitting device of the present invention. Shown in In FIG. 1, reference numeral 1 denotes a phosphor-containing portion (second light emitter), reference numeral 2 denotes a surface-emitting GaN-based LD as an excitation light source (first light emitter), and reference numeral 3 denotes a substrate. In order to create a state in which they are in contact with each other, LD (2) and phosphor-containing portion (second light emitter) (1) are produced separately, and their surfaces are brought into contact with each other by an adhesive or other means. Alternatively, the phosphor-containing portion (second light emitter) may be formed (molded) on the light emitting surface of the LD (2). As a result, the LD (2) and the phosphor-containing portion (second light emitter) (1) can be brought into contact with each other.

  When such an apparatus configuration is employed, the light loss is such that light from the excitation light source (first light emitter) is reflected by the film surface of the phosphor-containing portion (second light emitter) and oozes out. Therefore, the light emission efficiency of the entire device can be improved.

  FIG. 2A is a typical example of a light emitting device of a form generally referred to as a shell type, and has a light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the light emitting device (4), reference numeral 5 is a mount lead, reference numeral 6 is an inner lead, reference numeral 7 is an excitation light source (first light emitter), reference numeral 8 is a phosphor-containing resin portion, reference numeral 9 is a conductive wire, reference numeral Reference numeral 10 denotes a mold member.

  FIG. 2B is a representative example of a light-emitting device in a form called a surface-mount type, and light emission having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). It is typical sectional drawing which shows one Example of an apparatus. In the figure, reference numeral 22 is an excitation light source (first light emitter), reference numeral 23 is a phosphor-containing resin portion as a phosphor-containing portion (second light emitter), reference numeral 24 is a frame, reference numeral 25 is a conductive wire, Reference numerals 26 and 27 indicate electrodes.

[3-4. Application of light emitting device]
The application of the light-emitting device of the present invention is not particularly limited and can be used in various fields where ordinary light-emitting devices are used. However, since the color reproduction range is wide and the color rendering property is high, illumination is particularly important. It is particularly preferably used as a light source for a device or an image display device.

[3-4-1. Lighting device]
When the light-emitting device of the present invention is applied to a lighting device, the above-described light-emitting device may be appropriately incorporated into a known lighting device. For example, a surface-emitting illumination device (11) incorporating the above-described light-emitting device (4) as shown in FIG. 3 can be mentioned.

  FIG. 3 is a cross-sectional view schematically showing one embodiment of the illumination device of the present invention. As shown in FIG. 3, the surface-emitting illumination device has a number of light-emitting devices (13) (described above) on the bottom surface of a rectangular holding case (12) whose inner surface is light-opaque such as a white smooth surface. The light emitting device (4) corresponds to the lid portion of the holding case (12) by arranging a power source and a circuit (not shown) for driving the light emitting device (13) on the outside thereof. A diffuser plate (14) such as a milky white acrylic plate is fixed at a location for uniform light emission.

  Then, the surface emitting illumination device (11) is driven to apply light to the excitation light source (first light emitter) of the light emitting device (13) to emit light, and part of the light emission is converted into the phosphor. The phosphor in the phosphor-containing resin part as the containing part (second light emitter) absorbs and emits visible light, while having high color rendering due to color mixing with blue light or the like that is not absorbed by the phosphor. Luminescence is obtained, and this light is transmitted through the diffusion plate (14) and emitted upward in the drawing, so that illumination light with uniform brightness can be obtained within the surface of the diffusion plate (14) of the holding case (12). Become.

[3-4-2. Image display device]
When the light-emitting device of the present invention is applied to an image display device, the specific configuration of the image display device is not limited. For example, those shown in FIGS. 4 and 5 are exemplified as representative examples.

  FIG. 4 is an exploded cross-sectional view schematically illustrating a main part of the image display device according to an embodiment of the image display device of the present invention. In the display device shown in FIG. 4, it is assumed that the observer sees an image displayed on the display device from the right side in the figure.

The display device (15) of the present embodiment includes a light source (16) that emits excitation light and a phosphor part (17R) that contains a phosphor that absorbs light emitted from the light source (16) and emits visible light. , (17G), (17B). The display device (15) includes a frame (18), a polarizer (19), an optical shutter (20), and an analyzer (21).
Hereinafter, each member will be described.

[flame]
The frame (18) is a base for holding members such as the light source (16) constituting the display device (15), and its shape is arbitrary.
The material of the frame (18) is also arbitrary, and for example, an appropriate material such as an inorganic material such as a metal, an alloy, glass or carbon, or an organic material such as a synthetic resin can be used.

  However, from the viewpoint of effectively utilizing the light emitted from the light source (16) and improving the light emission efficiency of the display device (15), the surface of the frame (18) to which the light emitted from the light source (16) is applied is It is preferable that the reflectance of the hit light is increased. Therefore, it is preferable that at least the surface that is exposed to light is formed of a material having high reflectance. As a specific example, the entire frame (18) or the surface of the frame (18) is formed of a material (such as injection molding resin) containing a material having a high reflectance such as glass fiber, alumina powder, titania powder or the like. Is mentioned.

  The specific method for increasing the reflectivity of the surface of the frame (18) is arbitrary. In addition to selecting the material of the frame (18) itself as described above, for example, a high reflectivity of silver, platinum, aluminum, etc. The light reflectance can also be increased by plating or vapor deposition with a metal or alloy containing

  The part that increases the reflectivity may be the whole or a part of the frame (18), but usually the reflectivity of the entire surface of the part that is irradiated with the light emitted from the light source (16) is increased. It is desirable that

  Furthermore, the frame (18) is usually provided with electrodes and terminals for supplying power to the light source (16). At this time, means for connecting the electrode or terminal and the light source (16) is arbitrary, and for example, the light source (16) and the electrode or terminal can be connected by wire bonding to supply power. There is no restriction | limiting in the wire to be used, A raw material, a dimension, etc. are arbitrary. For example, a metal such as gold or aluminum can be used as the material of the wire, and the thickness can be usually 20 μm to 40 μm, but the wire is not limited to this.

  Another example of a method for supplying power to the light source (16) is a method for supplying power to the light source (16) by flip chip mounting using bumps.

  Further, when power is supplied to the light source (16), solder may be used. Since the solder exhibits excellent heat dissipation, a display device (15) is used when a high-current type LED or LD in which heat dissipation is important is used as an excitation light source (first light emitter) in the light source (16). This is because it is possible to improve the heat dissipation property. The type of solder is arbitrary, but, for example, AuSn, AgSn, or the like can be used.

  In addition to connecting to electrodes and terminals and using the power supply path, the solder may be used simply to install the light source (16) on the frame (18).

  Furthermore, when attaching the light source (16) to the frame (18) by means other than solder, for example, an adhesive such as epoxy resin, imide resin, or acrylic resin may be used. In this case, by using a paste in which conductive fillers such as silver particles and carbon particles are mixed into the adhesive, the adhesive is energized and power is supplied to the light source (16) as in the case of using solder. It is also possible to be able to supply. Furthermore, it is preferable to mix these conductive fillers because heat dissipation is improved.

  In the present embodiment, a flat frame (18) having a high surface reflectance is used, and a terminal (not shown) for supplying power to the light source (16) is provided on the surface. And In addition, it is assumed that power is supplied to the terminal from a power source (not shown).

[light source]
The light source (16) is positioned as the first light emitter that emits excitation light in the light emitting device of the present invention as described above. The light emitted from the light source (16) becomes excitation light that excites the phosphors contained in the phosphor parts (17R), (17G), and (17B). Furthermore, it is possible to allow the observer of the display device (15) to see the light itself emitted from the light source (16). In this case, the light emitted from the light source (16) is the light emitted from the pixels. It becomes itself.

  The wavelength of light emitted from the light source (16) can be any light in the ultraviolet region or visible region as long as the phosphors in the phosphor portions (17R), (17G), and (17B) can be excited. Can be used. When a desirable range of the wavelength of light emitted from the light source is given, the main emission peak wavelength is usually 350 nm or more, preferably 380 nm or more, more preferably 390 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 470 nm or less. If the lower limit of this range is exceeded, the liquid crystal substance itself may be destroyed by light emitted from the light source (16) when a liquid crystal light shutter is used as the light shutter (20). On the other hand, if the upper limit of the above range is exceeded, the luminous efficiency of the phosphor is lowered, and the luminance of the pixel may be lowered or the color reproduction range may be narrowed.

  When the wavelength of the excitation light emitted from the light source (16) is in the visible region, the light emitted from the light source (16) may be used as it is for displaying an image. In this case, the light shutter (20) adjusts the amount of light emitted from the light source (16), whereby the luminance of the pixel using the light emitted from the light source (16) is adjusted. For example, when the light source (16) emits blue light having a wavelength of 450 nm to 470 nm, the blue light can be used as light emitted from the pixels of the display device (15) as it is. However, in this case, since it is not necessary to perform wavelength conversion using a phosphor, there is no need for a phosphor portion corresponding to the blue pixel.

  Examples of the light source include an LED, a fluorescent lamp, an edge-emitting or surface-emitting LD, and an electroluminescence element. Of these, LEDs and fluorescent lamps are usually preferred. Furthermore, fluorescent lamps can use cold cathode tubes and hot cathode tubes that have been used in the past, but when white light is used, other colors are mixed into the blue, green, and red light emitting areas. It is desirable to extract only the near-ultraviolet region in white light using a filter or the like. In particular, it is particularly preferable to use a fluorescent lamp coated only with a near-ultraviolet phosphor to reduce power consumption.

Examples of the phosphor used in the fluorescent lamp include SrMgP ₂ O ₇ : Eu (emission wavelength 394 nm), Sr ₃ (PO ₄ ) ₂ : Eu (emission wavelength 408 nm), (Sr, Ba) Al ₂ Si ₂ O ₈ : Eu (emission wavelength 400 nm), Y ₂ Si ₂ O ₇ : Ce (emission wavelength 385 nm), ZnGa ₂ O ₄ : Li, Ti (emission wavelength 380 nm), YTaO ₄ : Nb (emission wavelength 400 nm), CaWO ₄ (emission wavelength) 410 nm), BaFX: Eu (X is halogen, emission wavelength 380 nm), (Sr, Ca) O.2B ₂ O ₃ : Eu (emission wavelength 380 to 450 nm), SrAl ₁₂ O ₁₄ : Eu (emission wavelength 400 nm), and Y ₂ SiO ₅ : Ce (emission wavelength 400 nm) and the like. In addition, these may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  On the other hand, as LEDs, high-intensity near-ultraviolet inorganic semiconductor LEDs can be obtained recently, and therefore backlights using these light sources can be used. In particular, near-ultraviolet emitting inorganic semiconductor LEDs can be suitably used because they can selectively emit light in a wavelength region preferable for the present invention. For example, a known single or multiple quantum well structure blue LED using InGaN as the light emitting layer, or a known single or multiple quantum well structure near ultraviolet LED using AlInGaN, GaN or AlGaN as the light emitting layer is preferable.

  Further, the light emitted from the light source (16) is directly incident on the phosphor portions (17R), (17G), and (17B), and is converted into planar light emission using a light guide plate or a light diffusion plate. The phosphor portions (17R), (17G), and (17B) may be incident on the phosphor portions (17R), (17G), and (17B). You may make it inject into. If a reflector is provided on the back surface of the light source (16) (the opposite side to the optical shutter (20)), as in the case of using a frame (18) having a high reflectance, the light source (16). The utilization efficiency of light emitted from can be increased.

The conversion mechanism for converting the light emitted from the light source (16) into planar light emission is arbitrary. For example, a light guide plate such as a quartz plate, a glass plate, or an acrylic plate, and a reflection mechanism such as an Al sheet or various metal deposition films. And a pattern using a TiO ₂ -based compound, a light diffusion mechanism such as a light diffusion sheet, a light diffusion prism and the like, and preferably a combination of a plurality of them. In particular, a conversion mechanism that converts the light into planar light by converting the light source (16) into a surface light emitter using a light guide plate, a reflection plate, a diffusion plate, or the like is preferably used in this embodiment. Further, for example, a conversion mechanism used for a liquid crystal display device or the like can also be suitably used.

  Furthermore, when installing the light source (16) on the frame (18), there is no limitation on the installation means, and any known means can be used. Therefore, as described above, for example, the light source (16) can be installed on the frame (18) using solder or the like.

  In the present embodiment, a surface light emitter emitting planar light is used as the light source (16). In addition, power is supplied to the light source (16) by electrically connecting the terminals on the frame (18) and the electrodes of the light source (16) using an interconnection circuit, wires, or the like. And

[Polarizer]
A polarizer (19) is preferably provided behind the light source (16) (left side in the figure), specifically between the light source (16) and the optical shutter (20). The polarizer (19) is provided to select only light in a predetermined direction from the light emitted from the light source (16). Also in this embodiment, it is assumed that the polarizer (19) is installed between the light source (16) and the optical shutter (20).

[Optical shutter]
In the present embodiment, the optical shutter (20) transmits irradiated light by adjusting the amount of light. Specifically, this is a member that adjusts the amount of light for each pixel and transmits the light irradiated on the back surface to the front corresponding to the image to be displayed. In the case of this embodiment, the optical shutter (20) adjusts the amount of light emitted from the light source (16) to the phosphor parts (17R), (17G), and (17B) and transmits the light forward. It is supposed to let you. Even when the light emitted from the light source (16) is used as it is as the pixel light, the light quantity emitted from the light source (16) is adjusted so as to be transmitted forward.

  More specifically, when the display device (15) is configured as a multi-color or full-color display, two or more types of the above-described phosphors are independently defined as light wavelength conversion mechanisms (that is, the phosphor portion (17R)). , (17G), (17B)). In the present embodiment, the phosphor portions (17R), (17G) are adjusted by adjusting the amount of excitation light irradiated to these phosphor portions (17R), (17G), (17B) by the optical shutter (20), respectively. , (17B) is adjusted so that a desired image can be displayed on the display device (15) with multicolor light emission.

  Further, depending on the type of the optical shutter (20), there is one in which the amount of light can be adjusted only for light in a specific wavelength region. Therefore, as the optical shutter (20), an optical shutter capable of switching light by adjusting the amount of light in the wavelength region of light emitted from the light source (16) is used. Depending on the configuration of the display device (15), not the light from the light source (16) but the light emitted from the phosphor parts (17R), (17G), (17B) may be adjusted to the light shutter (20). However, in that case, in the light wavelength region emitted from the phosphor portions (17R), (17G), and (17B), a light that can be switched by adjusting the light amount is used. . Usually, the center wavelength of the light emitted from the light source (16) and the light emitted from the phosphor portions (17R), (17G), (17B) is usually 350 nm or more, and usually 780 nm or less, preferably 420 nm or less. The optical shutter (20) is preferably capable of adjusting the amount of light in this wavelength range.

  Further, the mechanism of the optical shutter (20) is usually composed of an aggregate of a plurality of pixels (pixels). However, the number and size of pixels and the arrangement method vary depending on the screen size, display method, application, and the like, and are not particularly limited to constant values. Accordingly, there is no limitation on the size of the pixel of the optical shutter (20), and it is arbitrary as long as the effect of the present invention is not significantly impaired.

  For example, in a normal display application, the size of one pixel is preferably 500 μm square or less. Furthermore, as a suitable pixel size, it is more preferable that the number of pixels is about 640 × 3 × 480 and the single pixel size is about 100 μm × 300 μm as a value of a liquid crystal display currently in practical use.

  Further, the quantity and size of the optical shutter (20) itself are not limited and are arbitrary as long as the effects of the present invention are not significantly impaired. For example, the thickness of the optical shutter (20) is usually 5 cm or less, and preferably 1 cm or less in consideration of reduction in thickness and weight.

  When the display device (15) is a flat display device, an optical shutter (20) that changes the light transmittance of the pixel to an arbitrary value by electrical control is provided in order to enable gradation display. It can be used suitably. The higher the absolute value of the light transmittance, the contrast of the change and the speed response, the better.

  Examples of optical shutters (20) that satisfy these requirements include TFT (Thin Film Transistor), STN (Super Twisted Nematic liquid crystal), guest host using ferroelectric, antiferroelectric, dichroic dye, polymer dispersion PDN (Polymer Dispersed Network) type transmissive liquid crystal optical shutter; tungsten oxide, iridium oxide, Prussian blue, viologen derivative, TTF-polystyrene, rare earth metal-diphthalocyanine complex, polythiophene, polyaniline, etc. Examples include chromic and chemical chromic. Among them, a liquid crystal optical shutter is preferably used because it is thin, lightweight, and has low power consumption, has practical durability, and can increase the density of segments. Among these, a liquid crystal optical shutter using a TFT active matrix drive or a PDN method is particularly desirable. The reason is that the active matrix using twisted nematic liquid crystal does not cause high-speed response and crosstalk corresponding to moving images, and the PDN method does not require a polarizer (21). This is because light emission from (17R), (17G), and (17B) is small and light emission with high luminance becomes possible.

  The display device (15) is usually provided with a controller (not shown) that controls the optical shutter (20) so as to adjust the amount of light for each pixel in accordance with the image displayed on the display device (15). . The optical shutter (20) adjusts the amount of visible light emitted from each pixel in accordance with the control of the control unit, whereby a desired image is displayed on the display device (15).

  By adjusting the luminance of the pixels by the optical shutter (20), the display device (15) can make the control circuit of the control unit simpler. For example, when an LED is used as the light source (16) and the luminance of the pixel is adjusted by controlling the light emission intensity or the like of the LED, the current-luminance characteristics of the LED change with time, so the image to be displayed is controlled. The control circuit may be complicated. On the other hand, if a light shutter (20) portion for adjusting the amount of light emitted from the light source (16) is provided as in the present embodiment and the luminance of the pixel is adjusted by the light shutter (20), Since many optical shutters such as liquid crystal optical shutters are voltage controlled, the brightness can be adjusted with a simple control circuit.

  In the present embodiment, a liquid crystal optical shutter in which the back electrode (20-1), the liquid crystal layer (20-2), and the front electrode (20-3) are stacked in the above order is used as the optical shutter (20). The optical shutter (20) is provided in front of the polarizer (19) (right side in the figure). In addition, the back electrode (20-1) and the front electrode (20-3) shall be comprised with the transparent electrode which does not absorb the light used for a display apparatus (15). In this liquid crystal optical shutter, the molecular arrangement of the liquid crystal in the liquid crystal layer (20-2) is controlled by the voltage applied to the back electrode (20-1) and the front electrode (20-3), and the back surface is controlled by this molecular arrangement. The amount of light irradiated on the side is adjusted for each pixel (that is, for each phosphor portion (17R), (17G), and (17B)).

[Analyzer]
In front of the optical shutter (20), an analyzer (21) that receives light whose light amount is adjusted through the optical shutter (20) is usually provided. The analyzer (21) is for selecting light having passed through the optical shutter (20) and having only a certain polarization plane.

  Also in this embodiment, an analyzer (21) is provided in front of the optical shutter (20), specifically, between the optical shutter (20) and the phosphor portions (17R), (17G), and (17B). It shall be.

[Phosphor part]
The phosphor parts (17R), (17G), and (17B) absorb the excitation light emitted from the light source (16) and emit phosphors that emit visible light to form an image displayed on the display device (15). It is a part to contain. The phosphor portions (17R), (17G), and (17B) are normally provided one by one corresponding to the pixels, and generate light that is emitted from the pixels of the display device (15). Therefore, in this embodiment, the observer recognizes an image by looking at the fluorescence emitted from the phosphor portions (17R), (17G), and (17B).

  As the phosphor used in the phosphor part, any phosphor can be used as long as at least the green phosphor according to the present invention is used and the effects of the present invention are not significantly impaired. Specific examples of these phosphors include those exemplified as the first phosphor and the second phosphor described above.

  Further, the phosphor is used by blending one type or two or more types of phosphors. The emission color of the phosphor is not particularly limited because there is an appropriate color depending on the application, but blue, green, and red phosphors with high color purity are preferably used when, for example, a full color display is manufactured. There are several methods for expressing the appropriate color. For convenience, the center wavelength of light emission, CIE chromaticity coordinates, and the like are used. In addition, when the light wavelength conversion mechanism is monochrome display or multicolor display, it preferably includes a phosphor that develops colors of purple, blue-violet, yellow-green, yellow, and orange. Further, two or more of these phosphors may be mixed to emit light with high color purity, or to emit intermediate color or white light.

In addition, a binder is usually used for the phosphor portions (17R), (17G), and (17B) in order to protect the phosphor from external force or moisture from the external environment.
The binder is not particularly limited as long as it is usually used in this application, and a colorless and transparent material as described above as the liquid medium is used.

  In the phosphor parts (17R), (17G), and (17B), the ratio of the binder in the phosphor parts (17R), (17G), and (17B) is arbitrary as long as the effects of the present invention are not significantly impaired. However, it is usually 5 parts by weight or more, preferably 10 parts by weight or more, and usually 95 parts by weight or less, preferably 90 parts by weight or less with respect to 100 parts by weight of the phosphor. If the lower limit of this range is not reached, the phosphor parts (17R), (17G), and (17B) may be fragile, and if the upper limit is exceeded, the emission intensity may be reduced.

  Moreover, you may make the fluorescent substance part (17R), (17G), (17B) contain additives other than a binder and fluorescent substance. As an additive, for example, a diffusing agent may be included in order to further increase the viewing angle. Specific examples of the diffusing agent include barium titanate, titanium oxide, aluminum oxide, and silicon oxide. In addition, as an additive, for example, an organic or inorganic coloring dye or coloring pigment may be contained for the purpose of cutting an undesired wavelength. Each of these additives may be used alone or in combination of two or more in any combination and ratio.

  Further, the phosphor parts (17R), (17G), and (17B) can be produced by any known method. For example, the phosphor portions (17R), (17G), and (17B) are intervals corresponding to the pixels of the optical shutter (20) by applying a mixture (coating liquid) composed of a binder, a phosphor, and a solvent by screen printing. Thus, it can be formed on the transparent substrate (17-1) in a mosaic shape, an array shape, or a stripe shape.

  Moreover, you may form a black matrix layer (17-2) between each fluorescent substance part (17R), (17G), (17B) for absorption of external light. The black matrix layer (17-2) may be formed on a transparent substrate (17-1) such as glass by a process of manufacturing a light absorption film made of carbon black using the photosensitive principle of a photosensitive resin. Alternatively, a mixture of resin, carbon black, and solvent may be laminated by screen printing.

  The shapes of the phosphor parts (17R), (17G), and (17B) are arbitrary. For example, when the display device (15) is a multi-color display, the light emitting areas such as the phosphor portions (17R), (17G), and (17B) have a predetermined color according to the pixel shape of the optical shutter mechanism. The phosphors (17R), (17G), and (17B) include segment shapes and matrix shapes necessary for information display. Among them, a stripe structure, a delta structure, etc. can be mentioned as preferable forms. Furthermore, in the case of monochrome display, in addition to the above-mentioned shape, it is possible to apply a uniform phosphor.

  Furthermore, the dimensions of the phosphor parts (17R), (17G), and (17B) are also arbitrary. For example, the thickness is arbitrary as long as the effect of the present invention is not significantly impaired, but it can be suitably used when the thickness is usually 1 cm or less. Furthermore, in a flat panel display that is required to be thin and light, it is more preferable that the thickness be 2 mm or less. In particular, considering the balance with the emission rate of emitted light, the thickness of the phosphor parts (17R), (17G), (17B) is usually 1 μm or more, preferably 5 μm or more, more preferably 10 μm or more, and usually It is 1000 μm or less, preferably 500 μm or less, more preferably 200 μm or less.

  By the way, as described above, when visible light such as blue light is emitted from the light source (16), the visible light emitted from the light source (16) can be used as light emitted from the pixels. In that case, a phosphor portion that emits fluorescence of the same color as the light corresponding to the visible light is not essential. For example, when a blue light emitting LED is used as the light source (16), a phosphor part including a blue phosphor is unnecessary. Therefore, if the visible light emitted from the light source (16) is emitted outside the display device (15) by adjusting the light amount by the optical shutter, it is not always necessary to use the phosphor in all the pixels. . However, even in that case, the visible light emitted from the light source (16) is efficiently emitted to the outside, scattered, or the light having an undesired wavelength is cut. It is desirable to transmit the light transmitting part in which the binder contains an additive.

  The image display apparatus as described above causes the light source (16) to emit light at a predetermined intensity when in use. The light emitted from the light source (16) is incident on the optical shutter (20) after the plane of polarization is aligned by the polarizer (19).

  The optical shutter (20) adjusts the amount of light incident from the back side for each pixel according to the image to be displayed under the control of a control unit (not shown), and transmits the light forward. Specifically, by controlling the voltage applied to the transparent electrodes (20-1) and (20-3), the orientation of the liquid crystal at the site corresponding to each pixel is adjusted, and thus, The light received on the back surface is transmitted forward while adjusting whether or not the light of only the intensity is transmitted.

  The light that has passed through the optical shutter (20) enters the corresponding phosphor portions (17R), (17G), and (17B) through the analyzer (21), respectively.

  In the phosphor portion (17R), the red phosphor dispersed in the phosphor portion (17R) absorbs incident light and emits red fluorescence. In the phosphor part (17G), the green phosphor dispersed in the phosphor part (17G) absorbs incident light and emits green fluorescence. Further, in the phosphor part (17B), the blue phosphor dispersed in the phosphor part (17G) absorbs incident light and emits blue fluorescence.

  At this time, since the amount of incident light is adjusted for each pixel by the optical shutter (20) in accordance with the image to be formed, the fluorescence emitted from the phosphor portions (17R), (17G), and (17B). The amount of (visible light) is also adjusted for each pixel, and a desired image is formed.

  The red, green, and blue fluorescence generated in this way is emitted to the outside (right side in the figure) of the display device (15) through the transparent substrate (17-1). An observer sees the light emitted from the surface of the transparent substrate (17-1) and recognizes the image.

  By comprising as mentioned above, the image display apparatus (15) can suppress the photodegradation coloring of the binder contained in fluorescent substance part (17R), (17G), (17B). Therefore, it is possible to prevent the color and brightness of the image displayed by the image display device (15) from deteriorating with time.

  Furthermore, according to the display device, the amount of water in the phosphor portions (17R), (17G), and (17B) can be reduced, and therefore the phosphor portions (17R), (17G), and (17B). It is also possible to suppress deterioration of the inner phosphor.

  Also, according to the image display device (15), unlike the display device using the liquid crystal light shutter, it is possible to prevent the luminance of the pixel from being lowered or the color from being changed depending on the viewing angle.

  FIG. 5 explains another embodiment of the image display device of the present invention and is an exploded cross-sectional view schematically showing a main part of the image display device. In the display device shown in FIG. 5, it is assumed that the observer sees an image displayed on the display device from the right side in the figure. Further, in FIG. 5, parts indicated by the same reference numerals as those in FIG. 4 represent the same parts as in FIG.

  The image display device (15 ') in the image display device (15) has a phosphor portion between the light source (16) and the polarizer (19). Examples of the constituent members in the image display apparatus include the same ones as in the display apparatus (15) described above.

  Moreover, it is preferable that a black matrix (not shown) is provided between the pixels of the optical shutter (20). The black matrix has a function of making a gap between pixels black and making an image easy to see. As a material of the black matrix, for example, chromium, carbon, or a resin in which carbon or other black substance is dispersed is used, but the material is not limited thereto. In the present embodiment, since the observer sees the light transmitted through the optical shutter (20), this black matrix is provided in the optical shutter.

  In the display device (15 ′) of the present embodiment, since the arrangement order of the constituent members is changed as described above, the optical shutter (20) is moved from the phosphor portions (17R), (17G), and (17B). The amount of emitted light is adjusted for each pixel and transmitted forward. That is, the light emitted from the light source (16) is incident on the phosphor parts (17R), (17G), and (17B) to emit the phosphors in the phosphor parts (17R), (17G), and (17B). The light shutter (20) adjusts the amount of light emitted by the phosphors in the phosphor portions (17R), (17G), and (17B) for each pixel, and transmits the light forward. The display device (15 ′) can display a desired image with multicolor light emission by the light whose light amount has been adjusted by ().

  Therefore, in the image display device 15, an optical shutter (20) that can adjust the amount of light in the wavelength region of the light emitted from the light source (16) is used. However, the display device (15 In (1), a substance capable of adjusting the amount of light in the wavelength region of light emitted from the phosphor portions (17R), (17G), and (17B) is used. Specifically, in the optical shutter (20) of the present embodiment, the molecular arrangement of the liquid crystal in the liquid crystal layer (20-2) is controlled by the voltage applied to the back electrode (20-1) and the front electrode (20-3). The amount of light irradiated on the back side by this molecular arrangement is adjusted for each pixel.

  The light that has passed through the optical shutter (20) is applied to the analyzer (21). At this time, the amount of fluorescence emitted from the phosphor portions (17R), (17G), and (17B) is adjusted for each pixel by the optical shutter (20), and therefore the fluorescence irradiated to the analyzer (21). Will form the desired image. And an observer sees the light emitted from the surface of this analyzer (21), and recognizes an image.

  Furthermore, by configuring as described above, the image display device (15 ') can suppress the photodegradation coloring of the binder contained in the phosphor portions (17R), (17G), and (17B). Therefore, it is possible to prevent the color and brightness of the image displayed by the image display device (15 ') from deteriorating with time.

  Further, according to the image display device (15 ′), since the water in the phosphor portions (17R), (17G), (17B) can be reduced as compared with the conventional case, the phosphor portions (17R), (17 It is also possible to suppress the deterioration of the phosphors in 17G) and (17B).

Furthermore, according to the image display device (15 ′), unlike the display device using the conventional liquid crystal light shutter, it depends on the afterglow characteristics of the phosphors in the phosphor portions (17R), (17G), and (17B). The influence can be eliminated. The phosphor may emit fluorescence only for a predetermined time even after the light irradiation is stopped, and the time during which the fluorescence is emitted after the light irradiation is stopped is referred to as afterglow characteristics. Since afterglow characteristics differ depending on the phosphor, conventionally, a specific color tends to be emphasized in an image displayed on a display device, which has been a cause of high cost and complicated control. However, by adopting a configuration like the image display device (15 ′), it is possible to eliminate the influence of the afterglow characteristics and prevent the specific color of the image from being emphasized.
Furthermore, as with the image display device (15), the control circuit of the control unit can be simplified.

[Others]
The image display device of the present invention is not limited to the above-described embodiment of the image display device, and each configuration can be arbitrarily changed.
For example, in the above embodiment, the case where an image is displayed using three kinds of light of red, green, and blue has been described. However, the image display is performed using light other than the above red, green, and blue. In addition, image display may be performed using two types, or four or more types of light.

  Further, for example, in some pixels, the light emitted from the light source (16) may be directly used as pixel light.

  In addition to transmitting through the phosphor parts (17R), (17G), and (17B), light emitted from the light source (16) is reflected by the phosphor parts (17R), (17G), and (17B). Such a reflective configuration may be applied. Specifically, for example, in the image display device (15), the light source (16) can be installed in front of the phosphor portions (17R), (17G), and (17B).

  In addition to providing an optical shutter (20), a light source (16) is provided for each pixel, and the amount of light supplied to each light source (16) is adjusted to control the intensity of light emitted from the light source (16) for each pixel. In this way, the luminance of the pixel may be adjusted.

Further, the light source (16), phosphor parts (17R), (17G), (17B), frame (18), polarizer (19), optical shutter (20), analyzer (21), etc. Any combination can be used without departing from the scope of the present invention.
Moreover, you may use it for the image display apparatus of this invention combining another structural member further. For example, you may make it employ | adopt a protective film as it describes in the 0039th paragraph or less of Unexamined-Japanese-Patent No. 2005-885066.

In addition to the above members, films with various functions such as antireflection layers, alignment films, retardation films, brightness enhancement films, reflection films, transflective films, and light diffusion films can be added or laminated. You may do it.
The film having these optical functions can be formed, for example, by the following method.

  The layer having a function as a retardation film is subjected to, for example, a stretching process described in Japanese Patent No. 2841377, Japanese Patent No. 3094113, or a process described in Japanese Patent No. 3168850. Can be formed.

  The layer having a function as a brightness enhancement film may be formed by, for example, forming fine holes by a method described in JP-A No. 2002-169025 or JP-A No. 2003-29030, or selective reflection. It can be formed by superposing two or more cholesteric liquid crystal layers having different center wavelengths.

  Furthermore, the layer having a function as a reflective film or a transflective film can be formed using, for example, a metal thin film obtained by vapor deposition or sputtering.

  The layer having a function as a diffusion film can be formed by coating the protective film with a resin solution containing fine particles.

  Furthermore, the layer having a function as a retardation film or an optical compensation film can be formed by applying and aligning a liquid crystal compound such as a discotic liquid crystal compound or a nematic liquid crystal compound.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless it deviates from the summary.

[Examples 1-3 and Comparative Examples 1-2]
As phosphor raw materials, powders of barium carbonate (BaCO ₃ ), strontium carbonate (SrCO ₃ ), europium oxide (Eu ₂ O ₃ ), and silicon dioxide (SiO ₂ ) were used. All of these phosphor raw materials had a purity of 99.9% or more and a weight median diameter D _{50 in} the range of 10 nm or more and 5 μm or less. These phosphor materials were weighed so as to have the ratios shown in Examples 1 to 3 and Comparative Examples 1 and 2 in Table 2 below. These phosphor raw material powders were mixed in an automatic mortar until sufficiently uniform, filled in an alumina crucible, and fired at 1100 ° C. for 12 hours in a nitrogen atmosphere under atmospheric pressure. Next, the contents of the crucible were taken out, and SrCl ₂ as a flux was added so that the molar ratio with respect to silicon (Si) in the phosphor was 0.1, and dry-mixed. The obtained mixed pulverized product was again filled in an alumina crucible, and solid carbon (block shape) was placed thereon and covered. After reducing the pressure to 5 Pa with a vacuum pump in a vacuum furnace, hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) was introduced until atmospheric pressure was reached. After repeating this operation again, firing was performed by heating at 1200 ° C. for 6 hours under atmospheric pressure under flowing hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)). After the obtained fired product is crushed by a ball mill, coarse particles are removed through a sieve while in a slurry state, then washed with water, rinsed with water, washed away with fine particles, dried, and sieved to break up the agglomerated particles. The phosphor was manufactured by finishing.

  Moreover, the emission spectrum was measured about each phosphor obtained in Examples 1-3 and Comparative Examples 1-2.

  The emission spectrum was measured using a 150 W xenon lamp as an excitation light source and a fluorescence measuring device (manufactured by JASCO Corporation) equipped with a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring device. The light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 400 nm was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectroscope having a focal length of 25 cm, the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm to 800 nm, and a personal computer is used. An emission spectrum was obtained through signal processing such as sensitivity correction. During the measurement, the slit width of the light receiving side spectroscope was set to 1 nm and the measurement was performed.

From the obtained emission spectrum, the emission peak wavelength, the relative emission peak intensity, and the emission peak half width were determined. The relative emission peak intensity was expressed with the intensity of the emission peak when BaMgAl ₁₀ O ₁₇ : Eu (manufactured by Kasei Optonix, product number LP-B4) was excited at 365 nm as 100. The obtained emission peak wavelength, relative emission peak intensity, and emission peak half width are shown in Table 2 below.

  The relationship between the Ba / Sr value of the phosphor and the emission peak wavelength, relative emission peak intensity, and emission peak half-value width of the emission spectrum of the phosphor is shown in Table 2 below. Specifically, changes in the emission peak wavelength, the relative emission peak intensity, and the emission peak half-width when the Ba / Sr value was changed were shown for Examples and Comparative Examples having the same Eu concentration. From the results in Table 2 below, it can be seen that the emission peak wavelength shifts to the longer wavelength side and the emission peak half-value width increases as the ratio of Ba decreases.

Moreover, about each phosphor obtained in Examples 1 to 3 and Comparative Examples 1 to 2, an object color based on the L ^* a ^* b ^* color system was changed to a chromaticity meter (manufactured by Minolta, CR-300). It was used to measure the standard light as D _65. The obtained results are shown in Table 2 below.

Further, with respect to the phosphors obtained in Examples 1 to 3 and Comparative Examples 1 and 2, the absorption efficiency α _q , internal quantum efficiency η _i , and external quantum efficiency η _o of the phosphor were determined by the following procedure. .

  First, the phosphor sample to be measured was packed into a cell with a sufficiently smooth surface so that the measurement accuracy was maintained, and attached to the bottom hole of the integrating sphere.

  Light was introduced into this integrating sphere from an emission light source (150 W Xe lamp) for exciting the phosphor using an optical fiber. The light from the light emission source was adjusted using a monochromator (diffraction grating spectrometer) or the like so that the emission peak wavelength was monochromatic light at 455 nm. Using this monochromatic light as excitation light, the phosphor sample to be measured is irradiated from the upper hole of the integrating sphere, the fluorescence is taken out from the side hole with an optical fiber, and introduced into a spectrometer (MCPD7000 manufactured by Otsuka Electronics Co., Ltd.) The emission (fluorescence) and reflected light spectra of the sample were measured.

The absorption efficiency α _q is a value obtained by dividing the number of photons _Nabs of excitation light absorbed by the phosphor sample by the total number of photons N of excitation light.

First, the total number of photons N of the latter excitation light is proportional to the numerical value obtained by the following (formula I). Therefore, a “Spectralon” manufactured by Labsphere (having a reflectance R of 98% with respect to 450 nm excitation light), which is a reflector having a reflectance R of approximately 100% with respect to excitation light, is used as a measurement target. A reflection spectrum I _ref (λ) was measured by attaching to the integrating sphere described above in the same arrangement as the sample, irradiating excitation light, and measuring with a spectroscopic measurement device, and _obtaining the value of the following (formula I).

上記（式Ｉ）の積分区間は、４１０ｎｍ〜４８０ｎｍとした。

The integration interval of the above (formula I) was 410 nm to 480 nm.

On the other hand, number N _abs of the photons in the excitation light that is absorbed in the phosphor sample is proportional to the amount calculated by the following equation (II).

Therefore, the reflection spectrum I (λ) when the phosphor sample for which the absorption efficiency α _q is to be obtained was attached was obtained. The integration range of (Formula II) was the same as the integration range defined in (Formula I). Since the actual spectrum measurement value is generally obtained as digital data separated by a certain finite bandwidth with respect to λ, the integrals of (Equation I) and (Equation II) were obtained by summing based on the bandwidth. .
From the above results, the absorption efficiency α _q = N _abs / N = (Formula II) / (Formula I) was calculated.

Next, the internal quantum efficiency η _i was determined by the following procedure.
The internal quantum efficiency η _i is a value obtained by dividing the number of photons N _PL derived from the fluorescence phenomenon by the number of photons N _abs absorbed by the phosphor sample. Here, _NPL is proportional to the amount obtained by the following (formula III).

上記（式III）の積分区間は、４８１ｎｍ〜８００ｎｍとした。 Therefore, the amount required by the following (formula III) was determined.

The integration interval of the above (formula III) was 481 nm to 800 nm.

From the above results, the internal quantum efficiency η _i = (formula III) / (formula II) was calculated.
It should be noted that the integration from the digital data spectrum was performed in the same manner as when the absorption efficiency α _q was obtained.

Then, the external quantum efficiency η _o was obtained by taking the product of the absorption efficiency α _q and the internal quantum efficiency η _i obtained as described above.

Table 2 below shows the absorption efficiency α _q , internal quantum efficiency η _i , and external quantum efficiency η _o of the phosphors of Examples 1 to 6 and Comparative Examples 1 to 8 calculated by the above procedure.

From Table 2 above, it can be seen that the phosphors of Examples 1 to 3 are higher in external quantum efficiency η _o and superior in luminous efficiency than the phosphors of Comparative Examples 1 and 2.

Moreover, the following D value was calculated | required about each phosphor obtained in Examples 1-3 and Comparative Examples 1-2.
D = ((x−0.33) ² + (y−0.33) ² ) ^1/2
Here, x and y are the chromaticity coordinate x value and y value in the XYZ color system defined by JIS Z8701, and were calculated from data in the wavelength region of 480 nm to 800 nm of the emission spectrum of the phosphor. It can be seen that the phosphors of Examples 1 to 3 have a larger D value than the phosphors of Comparative Examples 1 and 2, and the color reproduction range is widened when an image display device is used.

  Moreover, the relative brightness | luminance and chromaticity coordinate were computed with the following method about each fluorescent substance obtained in Examples 1-3 and Comparative Examples 1-2. The results are shown in Table 2 below.

(Relative brightness)
Since the stimulus value Y defined by JIS Z8701 is proportional to the luminance, the relative value of the stimulus value Y is defined as the relative luminance. Incidentally, Y ₃ Al ₅ O _12: expressed Ce brightness when excited at 455nm (the Kasei Optonix Ltd. P46-Y3) as 100.

(Chromaticity coordinates)
Chromaticity coordinates x and y in the XYZ color system defined by JIS Z8701 were calculated from data in the wavelength region of 480 nm to 800 nm in the emission spectrum.

  The use of the phosphor of the present invention is not particularly limited, and can be used in various fields where ordinary phosphors are used, but takes advantage of its excellent conversion efficiency and color purity for blue light or near ultraviolet light. Therefore, it is suitable for the purpose of realizing a general illuminant that is excited by a light source such as a near-ultraviolet LED or a blue LED, particularly a white illuminant for a backlight having a high luminance and a wide color reproduction range.

  In addition, the light emitting device of the present invention using the phosphor of the present invention having the above-described characteristics can be used in various fields in which normal light emitting devices such as image display devices and illumination devices are used. It is particularly preferably used as a light source for an image display device.

It is a typical perspective view which shows the positional relationship of an excitation light source (1st light emission body) and a fluorescent substance containing part (2nd light emission body) in an example of the light-emitting device of this invention. 2 (a) and 2 (b) are schematic cross sections showing an embodiment of a light emitting device having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). FIG. It is sectional drawing which shows typically one Embodiment of the illuminating device of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded cross-sectional view schematically illustrating a main part of an image display device according to an embodiment of the image display device of the present invention. FIG. 5 is an exploded cross-sectional view schematically illustrating a main part of the image display device, for explaining another embodiment of the image display device of the present invention.

Explanation of symbols

1: Second light emitter 2: Surface-emitting GaN-based LD (first light emitter)
3: Substrate 4: Light emitting device 5: Mount lead 6: Inner lead 7: First light emitter 8: Phosphor-containing resin part 9: Conductive wire 10: Mold member 11: Surface emitting illumination device 12: Holding case 13: Light-emitting device 14: Diffusing plate 15, 15 ′: Display device 16: Light source 17R, 17G, 17B: Phosphor portion 17-1: Transparent substrate 17-2: Black matrix layer 18: Frame 19: Polarizer 20: Optical shutter 20 -1: Back electrode 20-2: Liquid crystal layer 20-3: Front electrode 21: Analyzer 22: First light emitter 23: Phosphor-containing resin part (second light emitter)
24: Frame 25: Conductive wire 26, 27: Electrode

Claims (20)

A phosphor having a chemical composition represented by the following formula [1].
(M ^I _(1-x) M ^II _x ) _α SiO _β [1]
(Wherein [1], M ^I is, Ba, Sr, Ca, selected from the group consisting of Zn and Mg, represents two or more elements including at least Ba and Sr. However, Ba and for the entire M ^I If Sr molar ratio of which is respectively [Ba] and [Sr], is in the range of [Ba] / value represented by [Sr] is 8.5 ≦ [Ba] / [Sr ] ≦ 100 .M II is Represents one or more metal elements that can have divalent and trivalent valences, where x, α, and β are 0.04 ≦ x <0.3, 1.5 ≦ α ≦ 2.5, and Represents a number satisfying 3.5 ≦ β ≦ 4.5.) In the formula [1], the [Ba] and [Sr] are
The phosphor according to claim 1, wherein 0.5 <{[Ba] / ([Ba] + [Sr])} <1 is satisfied. The phosphor according to claim 1 or 2, wherein in the formula [1], the [Ba] is 0.5 or more and less than 1. The D value represented by the following formula is
0.325 ≦ D ≦ 0.568
The phosphor according to any one of claims 1 to 3, wherein:
D = ((x−0.33) ² + (y−0.33) ² ) ^1/2
(Here, x and y are the chromaticity coordinate x value and y value in the XYZ color system defined by JIS Z8701, and values obtained from data in the wavelength region of 480 nm to 800 nm of the emission spectrum of the phosphor. .) When the object color is expressed in the L ^* a ^* b ^* color system, L ^* , a ^* , and b ^* are L ^* ≧ 90,
a ^* ≦ −20,
b ^* ≧ 30 and
{A ^* / b ^* } ≦ −0.45
The phosphor according to any one of claims 1 to 4, wherein: The phosphor according to any one of claims 1 to 5, wherein the phosphor is obtained by firing a phosphor precursor in the presence of a flux. The phosphor according to any one of claims 1 to 6, wherein the phosphor is obtained by firing a phosphor precursor in a strongly reducing atmosphere. The phosphor according to any one of claims 1 to 7, wherein the phosphor has a weight median diameter of 10 µm or more and 30 µm or less. In addition to the element described in the formula [1], at least one selected from the group consisting of a monovalent element, a divalent element, a trivalent element, a −1 valent element, and a −3 valent element. The phosphor according to any one of claims 1 to 8, wherein the phosphor contains seed elements, and the total content of these elements is 1 ppm or more. In addition to the elements described in the formula [1], an alkali metal element, an alkaline earth metal element, zinc (Zn), yttrium (Y), aluminum (Al), scandium (Sc), phosphorus (P), 10. The fluorescence according to claim 9, comprising at least one element selected from the group consisting of nitrogen (N), rare earth elements, and halogen elements, and the total content of these elements is 1 ppm or more. body. A method for producing the phosphor according to any one of claims 1 to 10,
A method for producing a phosphor, comprising a step of firing a phosphor precursor in an atmosphere having an oxygen concentration of 100 ppm or less. A method for producing the phosphor according to any one of claims 1 to 10,
A method for producing a phosphor, comprising a step of firing a phosphor precursor in the presence of solid carbon. A phosphor-containing composition comprising the phosphor according to any one of claims 1 to 10 and a liquid medium. A first light emitter, and a second light emitter that emits visible light by irradiation of light from the first light emitter,
A light-emitting device, wherein the second light-emitting body contains one or more kinds of the phosphors according to any one of claims 1 to 10 as a first phosphor. 15. The light emitting device according to claim 14, wherein the second phosphor includes, as the second phosphor, one or more phosphors having emission peak wavelengths different from those of the first phosphor. . The first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm;
16. The light emitting device according to claim 15, wherein the second light emitter contains at least one kind of phosphor having an emission peak in a wavelength range of 570 nm to 780 nm as the second phosphor. The first light emitter has a light emission peak in a wavelength range of 300 nm or more and 420 nm or less;
The second phosphor is, as the second phosphor, at least one phosphor having an emission peak in a wavelength range of 420 nm or more and 490 nm or less and at least one having an emission peak in a wavelength range of 570 nm or more and 780 nm or less. The light emitting device according to claim 15, further comprising a phosphor. The first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm;
16. The light emitting device according to claim 15, wherein the second luminous body contains at least one kind of phosphor having an emission peak in a wavelength range of 580 nm or more and 620 nm or less as the second phosphor. . An image display device comprising the light-emitting device according to claim 14 as a light source. An illumination device comprising the light emitting device according to any one of claims 14 to 18 as a light source.

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