JP2012241025A - Red phosphor, method for producing red phosphor, white light source, illuminating device, and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a red phosphor of high efficiency and a method for producing the same, to provide a white light source and an illumination device that enable illumination with the pure white color using the red phosphor, and to further provide a liquid crystal display device exhibiting good color reproducibility.SOLUTION: The red phosphor contains an alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O) and nitrogen (N) as main crystals, wherein a peak present at a position of the angle of diffraction of 36-36.6° in an X-ray diffraction pattern of the red phosphor exhibits a peak intensity ratio of ≥0.60 against a peak present at a position of the angle of diffraction of 35-36°.

Description

  The present invention relates to a red phosphor and a manufacturing method thereof, and further relates to a white light source, an illumination device, and a liquid crystal display device using the red phosphor.

  A white light source composed of a light emitting diode is used for a backlight of an illumination device or a liquid crystal display device. As such a white light source, a light source in which an yttrium aluminum garnet (hereinafter referred to as YAG: Ce) phosphor containing cerium is disposed on a light emitting surface side of a blue light emitting diode (hereinafter referred to as a blue LED) is known.

In addition to this, there is known one in which green and red sulfide phosphors are arranged on the light emitting surface side of a blue LED (for example, see Patent Document 1). Furthermore, a configuration is also proposed in which a fluorescent material formed by dissolving Mn, Eu, etc. in a CaAlSiN ₃ crystal is combined with other fluorescent materials in a predetermined ratio on the light emitting surface side of an LED emitting blue-violet or blue light. (For example, refer to Patent Document 2).

JP 2002-60747 A Japanese Patent No. 393239

  However, a white light source in which a YAG: Ce phosphor is disposed on the light emitting surface side of a blue LED has no red component in the emission spectrum of the YAG: Ce phosphor, resulting in bluish white light and a narrow color gamut. For this reason, it is difficult to perform pure white illumination with an illumination device configured using this white light source. Further, in a liquid crystal display device using this white light source as a backlight, it is difficult to perform display with good color reproducibility.

  Further, in a white light source in which green and red sulfide phosphors are arranged on the light emitting surface side of the blue LED, the luminance deteriorates with time because of the hydrolysis of the sulfide red phosphor. For this reason, it is difficult for a lighting device and a liquid crystal display device configured using this white light source to perform high-quality lighting and display in which deterioration of luminance is prevented.

Furthermore, in a white light source using a fluorescent material in which Mn, Eu or the like is dissolved in a CaAlSiN ₃ crystal, there is a trouble of using a mixture of two types of fluorescent materials.

  The present invention has been proposed in view of such circumstances, and provides a highly efficient red phosphor and a method for producing the same, a white light source capable of pure white illumination using the red phosphor, and It is an object of the present invention to provide an illumination device and also to provide a liquid crystal display device with good color reproducibility.

  As a result of intensive studies, the present inventors have found that in red phosphors containing europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N). In the X-ray diffraction pattern, the peak intensity existing at a diffraction angle of 36 ° to 36.6 ° is a crystal having a large peak intensity ratio with respect to the peak existing at a diffraction angle of 35 ° to 36 °. It has been found that high quantum efficiency can be obtained when it has a structure.

  That is, the red phosphor according to the present invention mainly contains the alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N). In the X-ray diffraction pattern included as a crystal, the intensity of a peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak intensity ratio with respect to a peak existing at a diffraction angle of 35 ° to 36 °. It indicates 0.60 or more.

  Further, the present invention provides a mixture by mixing a carbonate compound of alkaline earth metal element A, europium nitride, silicon nitride, aluminum nitride and a carbon-containing reducing agent, firing the mixture, and a fired product obtained by the firing Red fluorescence containing alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) as main crystals In the X-ray diffraction pattern, the intensity of a peak existing at a diffraction angle of 36 ° to 36.6 ° is a position where the diffraction angle is 35 ° to 36 °. A red phosphor exhibiting a peak intensity ratio of 0.60 or more with respect to the peak existing in is obtained.

  The white light source according to the present invention is a blue light emitting diode formed on an element substrate and a red phosphor and a green phosphor or a yellow phosphor disposed on the blue light emitting diode and kneaded in a transparent resin. The red phosphor includes alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N). In the X-ray diffraction pattern, the intensity of the peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak relative to the peak existing at a diffraction angle of 35 ° to 36 °. The intensity ratio is 0.60 or more.

  Further, in the illumination device according to the present invention, a plurality of white light sources are disposed on the illumination substrate, and the white light source is disposed on the element substrate, and the red light is disposed on the blue light emitting diode. It has a kneaded material in which a phosphor and a green phosphor or a yellow phosphor are kneaded in a transparent resin, and the red phosphor includes an alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), The intensity of a peak containing carbon (C), oxygen (O), and nitrogen (N) as a main crystal and having a diffraction angle of 36 ° to 36.6 ° in the X-ray diffraction pattern is The peak intensity ratio is 0.60 or more with respect to the peak existing at a position of 35 ° to 36 °.

  The liquid crystal display device according to the present invention includes a liquid crystal display panel and a backlight using a plurality of white light sources for illuminating the liquid crystal display panel, and the white light source is a blue color formed on an element substrate. A light-emitting diode, and a kneaded material disposed on the blue light-emitting diode and kneaded with a red phosphor and a green phosphor or a yellow phosphor in a transparent resin, the red phosphor comprising an alkaline earth metal element A, Europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) are included as main crystals, and an X-ray diffraction pattern has a diffraction angle of 36 ° to 36. The intensity of the peak existing at the 6 ° position shows a peak intensity ratio of 0.60 or more with respect to the peak existing at the diffraction angle of 35 ° to 36 °.

  The red phosphor according to the present invention has an emission peak wavelength in the red wavelength band and can emit red light with high efficiency due to the above-described characteristics.

  Further, since the white light source according to the present invention uses a highly efficient red phosphor, the red light by the red phosphor, the green light by the green phosphor or the yellow light by the yellow phosphor, and the blue light by the blue light emitting diode. Bright white light with a wide color gamut can be obtained by the light.

  Moreover, since the illuminating device according to the present invention uses a bright white light source with a wide color gamut, it can perform pure white illumination with high luminance.

  The liquid crystal display device according to the present invention illuminates the liquid crystal display panel using a bright white light source with a wide color gamut for the backlight that illuminates the liquid crystal display panel. White can be obtained, and display with high image quality with excellent color reproducibility can be performed.

It is a flowchart which shows the manufacturing method of the red fluorescent substance which concerns on one embodiment of this invention. It is a schematic sectional drawing which shows the white light source which concerns on one embodiment of this invention. It is a schematic plan view which shows the illuminating device which concerns on one embodiment of this invention. It is a schematic block diagram which shows the liquid crystal display device which concerns on one embodiment of this invention. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the peak wavelength It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the peak wavelength It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the peak wavelength It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the peak wavelength It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the peak wavelength It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. It is a figure which shows the emission spectrum of a red fluorescent substance when changing the addition amount of a melamine. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. The peak intensity of the melamine addition amount and the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with ratio. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the peak wavelength It is a figure which shows the relationship. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the relative luminance It is a figure which shows the relationship. It is a figure which shows the emission spectrum of a red fluorescent substance. It is a figure which shows the XRD spectrum of a red fluorescent substance. It is a graph which shows the peak intensity ratio of the intensity | strength of the peak in each diffraction angle with respect to the intensity | strength of the peak which exists in the position where a diffraction angle is 35.0 degrees-36.0 degrees. It is a figure which shows the PLE (Photoluminescence Excitation) spectrum when the emission intensity of the excitation wavelength of 400 nm of the red phosphor is 1. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °, and the external quantum It is a figure which shows the relationship with efficiency.

Hereinafter, embodiments of the present invention will be described in detail in the following order with reference to the drawings.
1. 1. Configuration of red phosphor 2. Manufacturing method of red phosphor 3. Configuration example of white light source 4. Configuration example of lighting device 5. Configuration example of liquid crystal display device Example

<1. Configuration of red phosphor>
The red phosphor according to one embodiment of the present invention includes alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N ) As a main crystal, and in the X-ray diffraction pattern, the intensity of the peak existing at the diffraction angle of 36 ° to 36.6 ° is higher than the peak existing at the diffraction angle of 35 ° to 36 °. The peak intensity ratio is 0.60 or more. By having a crystal structure exhibiting a peak intensity ratio in such a range, an external quantum efficiency exceeding 60% can be obtained. Note that the difference in peak intensity ratio means that the crystal structure of the red phosphor is different.

  The ratio of the peak intensity at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 ° is taken, that is, the diffraction angle is Increase / decrease in carbon content (melamine addition amount) by comparing large peaks present at positions of 36.0 ° to 36.6 ° and diffraction angles of 35.0 ° to 36.0 ° Accordingly, the increase / decrease in the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is increased. Detection sensitivity can be improved.

  The red phosphor contains an alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N), and the following composition formula (1) In the atomic ratio.

  However, in the composition formula (1), the alkaline earth metal element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba). In the composition formula (1), m, x, y, z, and n are 3 <m <5, 0 <x <1, 0 <y <2, 0 <z <1, 0 <n <10. Satisfy the relationship.

  The composition formula (1) is shown by fixing the total atomic ratio of silicon and carbon to 9. In addition, the atomic ratio [12 + y−2 (nm) / 3] of nitrogen (N) in the composition formula (1) is neutral when the sum of the atomic ratios of the respective elements in the composition formula (1) is neutral. It is calculated to be. That is, assuming that the atomic ratio of nitrogen (N) in the composition formula (1) is δ and the charge of each element constituting the composition formula (1) is compensated, 2 (mx) + 2x + 4 × 9 + 3y− 2n−3δ = 0. Accordingly, the atomic ratio of nitrogen (N) is calculated as δ = 12 + y−2 (n−m) / 3.

  The red phosphor represented by the composition formula (1) is composed of a crystal structure belonging to the orthorhombic space point group Pmn21, and contains carbon (C) as one of the constituent elements. By containing carbon, it functions to remove excess oxygen (O) in the production process and adjust the amount of oxygen.

  Further, in the composition formula (1), the alkaline earth metal element A includes at least one of magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba), and the atomic ratio of Ca is It is preferable to satisfy the relationship of 0 ≦ α / (α + β) ≦ 0.3, where β is the atomic ratio of α and Sr, and γ is the atomic ratio of the other group 2 elements (m = α + β + γ). By satisfying such a relationship, the quantum efficiency can be improved. When the calcium content (α / (α + β)) exceeds 0.3, it becomes difficult to obtain high quantum efficiency.

  In the composition formula (1), it is preferable to satisfy 0 <y ≦ 1.0. Quantum efficiency can be increased by setting the aluminum content (y) in such a range.

  Further, in the composition formula (1), it is preferable that 0.05 ≦ x ≦ 0.15 is satisfied. In the red phosphor shown in the composition formula (1), the peak of the emission intensity varies depending on the Eu (europium) concentration (x). By setting the Eu concentration (x) in this range, high quantum efficiency is achieved. Can be obtained.

<2. Manufacturing method of red phosphor>
Next, a method for manufacturing a red phosphor according to an embodiment of the present invention will be described below with reference to the flowchart shown in FIG.

As shown in FIG. 1, first, a “raw material mixing step” S1 is performed. In this raw material mixing step, first, melamine (C ₃ H ₆ N ₆ ) is mixed as a carbon raw material together with a raw material compound containing an element constituting the composition formula (1).

As a raw material compound containing an element constituting the composition formula (1), a carbonate compound of an alkaline earth metal element A [for example, strontium carbonate (SrCO ₃ ), calcium carbonate (CaCO ₃ )], europium nitride (EuN), nitriding Silicon (Si ₃ N ₄ ) and aluminum nitride (AlN) are prepared. Then, each compound is weighed in a predetermined molar ratio so that the element of composition formula (1) contained in each prepared raw material compound has the atomic ratio of composition formula (1). Each weighed compound is mixed to form a mixture. Melamine is added as a flux at a predetermined ratio with respect to the total number of moles of the carbonate compound of element A, europium nitride, aluminum nitride (AlN), and silicon nitride. Although representative examples are described here, oxide salts, halide salts, nitrates, acetates, phosphates, and the like can also be used as raw materials. Moreover, as a carbon raw material, it is not limited to a melamine, You may use other carbon containing reducing agents, such as urea.

  The mixture is produced, for example, by mixing in an agate mortar in a glow box in a nitrogen atmosphere.

Next, a “first heat treatment step” S2 is performed. In the first heat treatment step, the mixture is fired to produce a first fired product that becomes a precursor of the red phosphor. For example, the mixture is put in a boron nitride crucible and heat treatment is performed in a hydrogen (H ₂ ) atmosphere. In the first heat treatment step, for example, the heat treatment temperature is set to 1400 ° C. and the heat treatment is performed for 2 hours. The heat treatment temperature and heat treatment time can be appropriately changed within a range in which the mixture can be fired.

In the first heat treatment step, melamine having a melting point of 250 ° C. or lower is thermally decomposed. The pyrolyzed carbon (C) and hydrogen (H) are combined with a part of oxygen (O) contained in strontium carbonate to form carbon dioxide gas (CO or CO ₂ ) or H ₂ O (water). Since carbon dioxide gas and H ₂ O are vaporized, a part of oxygen is removed from the strontium carbonate of the first fired product. Reduction and nitridation are promoted by nitrogen (N) contained in the decomposed melamine.

  Next, “first crushing step” S3 is performed. In the first pulverization step, the first fired product is pulverized to produce a first powder. For example, the first fired product is pulverized using an agate mortar in a glow box in a nitrogen atmosphere, and then passed through, for example, # 100 mesh (aperture is about 200 μm) so that the average particle size is 3 μm or more. The first fired product having the following particle size is obtained. Thereby, it is made hard to produce a component nonuniformity in the 2nd baking products produced | generated by the 2nd heat processing of the following process.

Next, a “second heat treatment step” S4 is performed. In the second heat treatment step, the first powder is heat treated to produce a second fired product. For example, the first powder is put in a boron nitride crucible and heat treatment is performed in a nitrogen (N ₂ ) atmosphere. In the second heat treatment step, for example, the nitrogen atmosphere is pressurized to 0.85 MPa, the heat treatment temperature is set to 1800 ° C., and the heat treatment is performed for 2 hours. The heat treatment temperature and heat treatment time can be appropriately changed within a range where the first powder can be fired.

  By performing such a second heat treatment step, the red phosphor represented by the composition formula (1) is obtained. The second fired product (red phosphor) obtained by the second heat treatment step is a homogeneous product represented by the composition formula (1).

  Next, “second crushing step” S5 is performed. In the second pulverization step, the second fired product is pulverized to produce a second powder. For example, pulverization is performed using an agate mortar in a glow box in a nitrogen atmosphere, and the second fired product is made, for example, to an average particle diameter of about 3.5 μm using, for example, # 420 mesh (aperture is about 26 μm). Grind until

  A red phosphor of fine powder (for example, an average particle size of about 3.5 μm) is obtained by the method for producing a red phosphor. By powdering the red phosphor in this way, for example, when kneaded into a transparent resin together with the green phosphor powder, the red phosphor is uniformly kneaded.

  As described above, the red phosphor represented by the composition formula (1) containing each element at the atomic ratio mixed in the “raw material mixing step” S1 can be obtained. This red phosphor has a peak emission wavelength in a red wavelength band (for example, a wavelength band of 620 nm to 770 nm) as shown in the following examples.

<3. Configuration example of white light source>
Next, a white light source according to an embodiment of the present invention will be described with reference to a schematic cross-sectional view shown in FIG.

  As shown in FIG. 2, the white light source 1 has a blue light emitting diode 21 on a pad portion 12 formed on the element substrate 11. Electrodes 13 and 14 for supplying electric power for driving the blue light emitting diode 21 are formed on the element substrate 11 while maintaining insulation, and the electrodes 13 and 14 are, for example, blue light emitting diodes by lead wires 15 and 16. 21 is connected.

  Further, for example, a resin layer 31 is provided around the blue light emitting diode 21, and an opening 32 that opens on the blue light emitting diode 21 is formed in the resin layer 31. The opening 32 is formed on an inclined surface whose opening area is widened in the light emitting direction of the blue light emitting diode 21, and a reflective film 33 is formed on the inclined surface. That is, the resin layer 31 having the mortar-shaped opening 32 is covered with the wall reflecting film 33 of the opening 32 and the blue light emitting diode 21 is disposed on the bottom surface of the opening 32. Then, the white light source 1 is configured by embedding a kneaded material 43 in which the red phosphor and the green phosphor are mixed in a transparent resin so as to cover the blue light emitting diode 21 in the opening 32.

  As the red phosphor, the red phosphor represented by the composition formula (1) described above is used. This red phosphor has a peak emission wavelength in a red wavelength band (for example, a wavelength band of 620 nm to 770 nm), has high emission intensity, and high luminance. Therefore, it is possible to obtain bright white light having a wide color gamut by three primary colors including blue light of the blue LED, green light by the green phosphor, and red light by the red phosphor.

<4. Configuration Example of Lighting Device>
Next, the illuminating device which concerns on one embodiment of this invention is demonstrated using the schematic plan view of FIG.

  As shown in FIG. 3, in the illumination device 5, a plurality of white light sources 1 described with reference to FIG. 2 are arranged on the illumination substrate 51. The arrangement example may be, for example, a square lattice arrangement as shown in FIG. 3 (A), or an arrangement that is shifted every other row, for example, by 1/2 pitch as shown in FIG. 3 (B). Good. Further, the shifting pitch is not limited to 1/2, and may be 1/3 pitch or 1/4 pitch. Furthermore, you may shift every 1 line or every several lines (for example, 2 lines).

  Further, although not shown in the figure, the arrangement may be shifted every other column, for example, by 1/2 pitch. The shifting pitch is not limited to 1/2, and may be 1/3 pitch or 1/4 pitch. Further, it may be shifted every line or every plural lines (for example, 2 lines). That is, how to shift the white light source 1 is not limited.

  The white light source 1 has the same configuration as described with reference to FIG. That is, the white light source 1 has a kneaded material 43 obtained by kneading a red phosphor and a green phosphor in a transparent resin on the blue light emitting diode 21. As the red phosphor, the red phosphor represented by the composition formula (1) described above is used.

  Further, the illumination device 5 is equivalent to surface light emission because a plurality of white light sources 1 substantially equivalent to point light emission are arranged vertically and horizontally on the illumination substrate 51, and thus, for example, used as a backlight of a liquid crystal display device. be able to. Moreover, the illuminating device 5 can be used for various illuminating devices such as a normal illuminating device, a photographing illuminating device, and a construction site illuminating device.

  Since the illuminating device 5 uses the white light source 1, it can obtain bright white light with a wide color gamut. For example, when used for a backlight of a liquid crystal display device, pure white with high luminance can be obtained on the display screen, and the quality of the display screen can be improved.

<5. Configuration example of liquid crystal display device>
Next, a liquid crystal display device according to an embodiment of the present invention will be described with reference to the schematic configuration diagram of FIG.

  As shown in FIG. 4, the liquid crystal display device 100 includes a liquid crystal display panel 110 having a transmissive display portion, and a backlight 120 having the liquid crystal display panel 110 on the back surface (the surface opposite to the display surface). Have. As the backlight 120, the illumination device 5 described with reference to FIG. 3 is used.

  In the liquid crystal display device 100, since the illumination device 5 is used for the backlight 120, the liquid crystal display panel 110 can be illuminated with bright white light having a wide color gamut based on the three primary colors of light. Therefore, pure white with high luminance can be obtained on the display screen of the liquid crystal display panel 110, color reproducibility is good, and the quality of the display screen can be improved.

  Examples of the present invention will be described below. Here, red phosphors having different compositions were prepared, and the X-ray diffraction pattern and quantum efficiency of these red phosphors were evaluated. The present invention is not limited to these examples.

[Production of red phosphor]
Alkaline earth metal element A, Europium (Eu), Silicon (Si), Carbon (C), Aluminum (Al), Oxygen (O), and Nitrogen (N) in the atomic ratio of the following composition formula (1) The red phosphor contained was produced as follows according to the procedure described using the flowchart shown in FIG.

  However, in the composition formula (1), the alkaline earth metal element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba). In the composition formula (1), m, x, y, z, and n are 3 <m <5, 0 <x <1, 0 <y <2, 0 <z <1, 0 <n <10. Satisfy the relationship. Further, when the atomic ratio of Ca is α, the atomic ratio of Sr is β, and the atomic ratio of other group 2 elements is γ, m = α + β + γ is satisfied.

First, the “raw material mixing step” S1 was performed. Here, calcium carbonate (CaCO ₃ ), strontium carbonate (SrCO ₃ ), europium nitride (EuN), silicon nitride (Si ₃ N ₄ ), aluminum nitride (AlN) and melamine (C ₃ H ₆ N ₆ ) were prepared. . Each prepared raw material compound was weighed and mixed in an agate mortar in a glow box in a nitrogen atmosphere.

Next, “first heat treatment step” S2 was performed. Here, the above mixture was put in a boron nitride crucible, and heat treatment was performed at 1400 ° C. for 2 hours in a hydrogen (H ₂ ) atmosphere.

  Next, “first pulverization step” S3 was performed. Here, in a glow box in a nitrogen atmosphere, the first fired product is pulverized using an agate mortar, and then passed through # 100 mesh (aperture is about 200 μm), and the average particle size is 3 μm or less. A first fired product having a particle size was obtained.

Next, “second heat treatment step” S4 was performed. Here, the powder of the first fired product was placed in a boron nitride crucible and heat-treated at 1800 ° C. for 2 hours in a nitrogen (N ₂ ) atmosphere of 0.85 MPa. As a result, a second fired product was obtained.

  Next, “second crushing step” S5 was performed. Here, the second fired product was pulverized using an agate mortar in a glow box in a nitrogen atmosphere. Using a # 420 mesh (aperture of about 26 μm), it was pulverized until the average particle size was about 3.5 μm.

  By such a method, a red phosphor having a fine powder (for example, an average particle diameter of about 3.5 μm) was obtained. The elements A, Eu, Si, and Al in the red phosphor are analyzed by an ICP (Inductively Coupled Plasma) emission analyzer, and C is analyzed by an ICP emission analyzer and an oxygen gas combustion-NDIR detection system (device: EMIA). -U511 (Horiba Seisakusho)). As a result of analyzing this red phosphor with an ICP emission analyzer, the elements A, Eu, Si, and Al constituting the composition formula (1) contained in the raw material compound are almost in the same molar ratio (atomic ratio). ) To be contained in the red phosphor.

  The content (z) of carbon in the red phosphor satisfies the relationship of 0 <z <1 as a result of analysis using an ICP emission analyzer and combustion in an oxygen stream-NDIR detection method. It was confirmed that it increased accordingly. The minimum carbon content (z) was 0.012.

[Evaluation of X-ray diffraction pattern and quantum efficiency for carbon content and calcium content]
About each red fluorescent substance, the X-ray-diffraction pattern and quantum efficiency when changing melamine addition amount and calcium content were measured. The X-ray diffraction pattern was examined using a powder X-ray analyzer (manufactured by Rigaku Corporation). The quantum efficiency was measured using a spectrofluorometer FP-6500 manufactured by JASCO Corporation. A dedicated cell was filled with phosphor powder, irradiated with blue excitation light having a wavelength of 450 nm, and a fluorescence spectrum was measured. The red quantum efficiency was calculated from the result using the quantum efficiency measurement software attached to the spectrofluorometer. The efficiency of the phosphor is, for example, the efficiency of absorbing the excitation light (absorption rate), the efficiency of converting the absorbed excitation light into fluorescence (internal quantum efficiency), and the efficiency of converting the product of the excitation light into fluorescence ( The external quantum efficiency is important. Here, important external quantum efficiencies were calculated.

<Calcium content (α / (α + β)) = 0, aluminum content (y) = 0.4376>
FIG. 5 is a diagram showing an emission spectrum of the red phosphor when the amount of melamine added is changed. FIG. 5 shows each red phosphor (m = 3.789, Eu concentration (x) = 0.142) with a calcium content (α / (α + β)) of 0 and an aluminum content (y) = 0.4736. , Γ = 0). As shown in FIG. 5, it was found that as the amount of melamine added was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  6 and 7 are diagrams showing the XRD spectrum of the red phosphor. FIG. 8 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle with respect to the peak intensity existing at a diffraction angle of 35.0 ° to 36.0 °. Table 1 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 2 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 6 to 8, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, near 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It turned out that it became strong in proportion to.

  FIG. 9 shows the amount of melamine added and the peak at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It turned out that the peak intensity ratio of intensity | strength becomes strong.

  Further, it is substantially proportional to the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the peak wavelength shifted to the short wavelength side.

  FIG. 10 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the external quantum efficiency is improved. Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. It was found that in the range of 30 or more, the external quantum efficiency exceeded 60%.

  FIG. 11 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. Proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It was found that the relative luminance was improved.

<Calcium content (α / (α + β)) = 0.1, Aluminum content (y) = 0.4736>
FIG. 12 is a diagram showing an emission spectrum of the red phosphor when the amount of melamine added is changed. FIG. 12 shows each red phosphor (m = 3.789, Eu concentration (x) = 0) with a calcium content (α / (α + β)) of 0.1 and an aluminum content (y) = 0.4736. .142, γ = 0). As shown in FIG. 12, it was found that as the amount of melamine added was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  13 and 14 are diagrams showing the XRD spectrum of the red phosphor. FIG. 15 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 3 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 4 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 13 to 15, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, near 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It turned out that it became strong in proportion to.

  FIG. 16 shows the peak of the diffraction angle at the position of 36.0 ° to 36.6 ° with respect to the amount of melamine added and the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It was found that the peak intensity ratio became stronger.

  FIG. 17 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and a peak wavelength. As shown in FIG. 17, the peak intensity of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °. It was found that the peak wavelength shifts to the short wavelength side almost in proportion to the ratio.

  FIG. 18 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is 0.65. Up to the vicinity, it was found that the external quantum efficiency was improved in proportion to the peak intensity ratio. Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. In the range of 60 or more, it was found that the external quantum efficiency exceeded 60%.

  FIG. 19 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the relative luminance was improved.

<Calcium content (α / (α + β)) = 0.2, Aluminum content (y) = 0.4736>
FIG. 20 is a diagram showing an emission spectrum of the red phosphor when the amount of melamine added is changed. FIG. 20 shows that each red phosphor having a calcium content (α / (α + β)) of 0.2 and an aluminum content (y) = 0.4376 (m = 3.789, Eu concentration (x) = 0). .142, γ = 0). As shown in FIG. 20, it was found that as the amount of melamine added was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  21 and 22 are diagrams showing XRD spectra of the red phosphor. FIG. 23 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 5 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 6 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 21 to 23, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, near 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It turned out that it became strong in proportion to.

  FIG. 24 shows the peak of the diffraction angle at the position of 36.0 ° to 36.6 ° with respect to the amount of melamine added and the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It turned out that the peak intensity ratio of intensity | strength becomes strong.

  FIG. 25 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and a peak wavelength. As shown in FIG. 25, the peak intensity of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °. It was found that the peak wavelength shifts to the short wavelength side almost in proportion to the ratio.

  FIG. 26 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. Proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It was found that the external quantum efficiency was improved. It was also found that the external quantum efficiency exceeded 60% when the peak intensity ratio was about 0.60 or more.

  FIG. 27 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the relative luminance was improved.

<Calcium content (α / (α + β)) = 0.3, Aluminum content (y) = 0.4736>
FIG. 28 is a diagram showing an emission spectrum of the red phosphor when the amount of melamine added is changed. FIG. 28 shows that each red phosphor (m = 3.789, Eu concentration (x) = 0) having a calcium content (α / (α + β)) of 0.3 and an aluminum content (y) = 0.4736. .142, γ = 0). As shown in FIG. 28, it was found that as the amount of melamine added was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  29 and 30 are diagrams showing XRD spectra of the red phosphor. FIG. 31 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle with respect to the peak intensity existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 7 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 8 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 29 to 31, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, around 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It turned out that it became strong in proportion to.

  FIG. 32 shows the peak of the diffraction angle at the position of 36.0 ° to 36.6 ° with respect to the amount of melamine added and the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It turned out that the peak intensity ratio of intensity | strength becomes strong.

  FIG. 33 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and a peak wavelength. As shown in FIG. 33, the peak intensity of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °. It was found that the peak wavelength shifted to the short wavelength side in proportion to the peak intensity ratio up to about 0.82.

  FIG. 34 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the external quantum efficiency is improved. It was also found that the external quantum efficiency exceeded 60% when the peak intensity ratio was about 0.69 or more.

  FIG. 35 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the relative luminance was improved.

<Summary in Case of Calcium Content (α / (α + β)) = 0, 0.1, 0.2, 0.3, Aluminum Content (y) = 0.4736>
FIG. 36 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency.

  In a range where the aluminum content (y) = 0.4376 and the calcium content (α / (α + β)) satisfy the relationship of 0 ≦ α / (α + β) ≦ 0.3, the diffraction angle is 35.0 °. The external quantum efficiency is improved in proportion to the peak intensity ratio of the intensity of the peak existing at the position where the diffraction angle is 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the position of −36.0 °. I understood that.

  Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. It was found that in the range of 30 or more, the external quantum efficiency exceeded 60%.

  Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is about 0.000. It was found that in the range of 60 or more, the result that the external quantum efficiency exceeds 65% is almost obtained.

<Calcium content (α / (α + β)) = 0.1, Aluminum content (y) = 1.0>
FIG. 37 is a diagram showing an emission spectrum of the red phosphor when the melamine addition amount is changed. FIG. 38 shows each red phosphor (m = 4, Eu concentration (x) = 0.15) with a calcium content (α / (α + β)) of 0.1 and an aluminum content (y) = 1.0. , Γ = 0). As shown in FIG. 37, it was found that as the amount of melamine added was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  38 and 39 are diagrams showing the XRD spectrum of the red phosphor. FIG. 40 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 9 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 10 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 38 to 40, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, near 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It turned out that it became strong in proportion to.

  FIG. 41 shows the peak of the diffraction angle at the position of 36.0 ° to 36.6 ° with respect to the amount of melamine added and the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It was found that the peak intensity ratio became stronger.

  FIG. 42 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and a peak wavelength. As shown in FIG. 42, the peak intensity of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °. It was found that the peak wavelength shifts to the short wavelength side almost in proportion to the ratio.

  FIG. 43 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is 0.90. Up to the vicinity, it was found that the external quantum efficiency was improved in proportion to the peak intensity ratio. Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. It was found that in the range of 70 or more, the external quantum efficiency exceeded 60%.

  FIG. 44 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is 0.90. It was found that the relative luminance was improved up to the vicinity.

<Calcium content (α / (α + β)) = 0.15, Aluminum content (y) = 1.0>
FIG. 45 is a diagram showing an emission spectrum of the red phosphor when the amount of melamine added is changed. FIG. 45 shows each red phosphor (m = 4, Eu concentration (x) = 0.15) with a calcium content (α / (α + β)) of 0.15 and an aluminum content (y) = 1.0. , Γ = 0). As shown in FIG. 45, it was found that as the addition amount of melamine, that is, the melamine was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  46 and 47 are diagrams showing the XRD spectrum of the red phosphor. FIG. 48 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 11 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 12 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 46 to 48, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, near 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It turned out that it became strong in proportion to.

  FIG. 49 shows the peak of the diffraction angle at the position of 36.0 ° to 36.6 ° with respect to the amount of melamine added and the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It was found that the peak intensity ratio became stronger.

  FIG. 50 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and a peak wavelength. As shown in FIG. 50, the peak intensity of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °. It was found that the peak wavelength shifts to the short wavelength side almost in proportion to the ratio.

  FIG. 51 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is about 0.000. It was found that in the range of 70 to 1.0, the external quantum efficiency is improved almost in proportion to the peak intensity ratio. Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. It was found that in the range of 70 or more, the external quantum efficiency exceeded 60%.

  52 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. The peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is about 0.000. It was found that in the range of 70 to 1.0, the relative luminance was improved almost in proportion to the peak intensity ratio.

<Calcium content (α / (α + β)) = 0.25, aluminum content (y) = 1.0>
FIG. 53 is a diagram showing an emission spectrum of the red phosphor when the amount of melamine added is changed. FIG. 53 shows each red phosphor (m = 4, Eu concentration (x) = 0.15) with a calcium content (α / (α + β)) of 0.25 and an aluminum content (y) = 1.0. , Γ = 0). As shown in FIG. 53, it was found that as the amount of melamine added was increased, the emission intensity was improved and the emission was shifted to the short wavelength side.

  54 and 55 are diagrams showing the XRD spectrum of the red phosphor. FIG. 56 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 13 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 14 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 54 to 56, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, around 2θ = 35.5 °, and the diffraction angle is There is a peak corresponding to the (122) plane at a position of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °, and the intensity of the peak near 2θ = 36.3 ° is the amount of melamine added. It became clear that it became stronger in proportion to.

  FIG. 57 shows the peak of the diffraction angle at the position of 36.0 ° to 36.6 ° with respect to the amount of melamine added and the intensity of the peak at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship with the peak intensity ratio of intensity | strength. The peak of the peak at a diffraction angle of 36.0 ° to 36.6 ° relative to the intensity of the peak at a diffraction angle of 35.0 ° to 36.0 ° is approximately proportional to the amount of melamine added. It was found that the peak intensity ratio became stronger.

  FIG. 58 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and a peak wavelength. As shown in FIG. 58, the peak intensity of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °. It was found that the peak wavelength shifts to the short wavelength side almost in proportion to the ratio.

  FIG. 59 shows a peak intensity ratio of the intensity of a peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of a peak existing at a diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the external quantum efficiency is improved. Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. In the range of 60 or more, it was found that the external quantum efficiency exceeded 60%.

  FIG. 60 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and relative luminance. It is approximately proportional to the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. Thus, it was found that the relative luminance was improved.

<Calcium content (α / (α + β)) = 0, aluminum content (y) = 1.0>
FIG. 61 is a diagram showing an emission spectrum of the red phosphor. FIG. 61 shows red phosphors (m = 4, Eu concentration (x) = 0.15, γ) in which the calcium content (α / (α + β)) is 0 and the aluminum content (y) = 1.0. = 0). From the results shown in FIG. 61, it was found that the peak wavelength (λ _p ) was 639 nm, the peak intensity was 1.74 cps, and the half width (FWHM) of the emission spectrum was 102 nm. The chromaticity x was 0.655, the chromaticity y was 0.344, and the relative luminance Y was 43.0. Further, the integrated value of light emission was 191.37 cps, the external quantum efficiency was 67.19%, the sample absorption rate was 88.97%, and the internal quantum efficiency was 75.52%.

  FIG. 62 is a diagram showing an XRD spectrum of a red phosphor. FIG. 63 is a graph showing the peak intensity ratio of the peak intensity at each diffraction angle to the intensity of the peak existing at a diffraction angle of 35.0 ° to 36.0 °.

  Table 15 shows the melamine addition amount and the relative ratio of the diffraction intensity, and Table 16 shows the melamine addition amount and the angle at which the diffraction intensity was actually obtained.

  As shown in FIGS. 62 and 63, there is a peak corresponding to the (113) plane at a diffraction angle of 35.0 ° to 36.0 °, that is, around 2θ = 35.5 °. It was found that there was a peak corresponding to the (122) plane at a folding angle of 36.0 ° to 36.6 °, that is, in the vicinity of 2θ = 36.3 °.

  FIG. 64 is a diagram showing a PLE spectrum when the emission intensity of the red phosphor at an excitation wavelength of 400 nm is 1. As shown in FIG. The PLE spectrum is a spectrum that shows how the intensity changes when the excitation wavelength is changed, focusing on PL (Photoluminescence) emission intensity of a specific energy.

<Summary in Case of Calcium Content (α / (α + β)) = 0.1, 0.15, 0.25, Aluminum Content (y) = 1.0>
FIG. 65 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency.

  When the aluminum content (y) = 1.0 and the calcium content (α / (α + β)) satisfy the relationship of 0 ≦ α / (α + β) ≦ 0.3, the diffraction angle is 35.0 °. The external quantum efficiency is improved in proportion to the peak intensity ratio of the intensity of the peak existing at the position where the diffraction angle is 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the position of −36.0 °. I understood that.

  Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is approximately 0.00. In the range of 60 or more, it was found that the external quantum efficiency exceeded 60%.

  Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is about 0.000. In the range of 80 or more, it was found that the result that the external quantum efficiency exceeds 65% is almost obtained.

<Summary in Case of Calcium Content (α / (α + β)) 0 ≦ α / (α + β) ≦ 0.3 and Aluminum Content (y) 0 <y ≦ 1.0>
FIG. 66 shows the peak intensity ratio of the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 °. It is a figure which shows the relationship between and external quantum efficiency.

  In a range where the aluminum content (y) satisfies the relationship 0 <y ≦ 1.0 and the calcium content (α / (α + β)) satisfies 0 ≦ α / (α + β) ≦ 0.3, the diffraction angle The peak intensity ratio of the peak existing at a diffraction angle of 36.0 ° to 36.6 ° with respect to the intensity of the peak existing at a position of 35.0 ° to 36.0 ° is about 0.60 or more. , It was found that the external quantum efficiency exceeded 60%.

  Further, the peak intensity ratio of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° to the intensity of the peak existing at the diffraction angle of 35.0 ° to 36.0 ° is about 0.000. It was found that in the range of 75 or more, the result that the external quantum efficiency exceeds 65% is almost obtained.

  The above results show that in the X-ray diffraction pattern, the intensity of the peak existing at the diffraction angle of 36.0 ° to 36.6 ° is at the diffraction angle of 35.0 ° to 36.0 °. It is considered that a crystal structure having a peak intensity ratio larger than a predetermined value with respect to an existing peak contributes to high quantum efficiency.

  DESCRIPTION OF SYMBOLS 1 White light source, 5 Illumination device, 21 Blue light emitting diode, 43 Kneaded material, 100 Liquid crystal display device, 110 Liquid crystal display panel, 120 Backlight (illumination device 5)

Claims (8)

An alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) as main crystals,
In the X-ray diffraction pattern, the intensity of the peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak intensity ratio of 0.60 or more with respect to the peak existing at a diffraction angle of 35 ° to 36 °. Red phosphor showing. Alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al) carbon (C), oxygen (O), and nitrogen (N) are contained in the atomic ratio of the following composition formula (1). The red phosphor according to claim 1.

However, in the composition formula (1), the alkaline earth metal element A is at least one of magnesium (Mg), calcium (Ca), strontium (Sr), or barium (Ba). In the composition formula (1), m, x, y, z, and n are 3 <m <5, 0 <x <1, 0 <y <2, 0 <z <1, 0 <n <10. Satisfy the relationship. The alkaline earth metal element A contains at least calcium (Ca) and strontium (Sr),
When the atomic ratio of Ca is α, the atomic ratio of Sr is β, and the atomic ratio of other group 2 elements is γ (m = α + β + γ), the relationship 0 ≦ α / (α + β) ≦ 0.3 is established. The red phosphor according to claim 1 or 2, which is satisfied.   The red phosphor according to claim 2, wherein the compound represented by the composition formula (1) is composed of a crystal structure belonging to an orthorhombic space point group Pmn21. A mixture of an alkaline earth metal element A carbonate compound, europium nitride, silicon nitride, aluminum nitride and a carbon-containing reducing agent,
Firing the mixture and grinding the fired product obtained by the firing,
Red fluorescence for producing a red phosphor containing the alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) as main crystals A method for manufacturing a body,
In the X-ray diffraction pattern, the intensity of the peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak intensity ratio of 0.60 or more with respect to the peak existing at a diffraction angle of 35 ° to 36 °. The manufacturing method of the red fluorescent substance which obtains the red fluorescent substance which shows. A blue light emitting diode formed on the element substrate;
A kneaded material disposed on the blue light emitting diode and kneaded with a red phosphor and a green phosphor or a yellow phosphor in a transparent resin;
The red phosphor is
An alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) as main crystals,
In the X-ray diffraction pattern, the intensity of the peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak intensity ratio of 0.60 or more with respect to the peak existing at a diffraction angle of 35 ° to 36 °. Showing white light source. An illumination device in which a plurality of white light sources are arranged on an illumination substrate,
The white light source is
A blue light emitting diode formed on the element substrate;
A kneaded material arranged on the blue light emitting diode and kneaded with a red phosphor and a green phosphor or a yellow phosphor in a transparent resin,
The red phosphor is
An alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) as main crystals,
In the X-ray diffraction pattern, the intensity of the peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak intensity ratio of 0.60 or more with respect to the peak existing at a diffraction angle of 35 ° to 36 °. Illuminating device showing. A liquid crystal display panel;
A backlight using a plurality of white light sources for illuminating the liquid crystal display panel;
The white light source is
A blue light emitting diode formed on the element substrate;
A kneaded material arranged on the blue light emitting diode and kneaded with a red phosphor and a green phosphor or a yellow phosphor in a transparent resin,
The red phosphor is
An alkaline earth metal element A, europium (Eu), silicon (Si), aluminum (Al), carbon (C), oxygen (O), and nitrogen (N) as main crystals,
In the X-ray diffraction pattern, the intensity of the peak existing at a diffraction angle of 36 ° to 36.6 ° is a peak intensity ratio of 0.60 or more with respect to the peak existing at a diffraction angle of 35 ° to 36 °. A liquid crystal display device.

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