KR20130055360A - A lutetium-aluminium perovskite phosphor materials and their applications for white-light-emitting device - Google Patents

Abstract

PURPOSE: A ruthenium-aluminum perovskite-based phosphor for blue light excitation is provided to emit green and yellow light with excellent luminance efficiency. CONSTITUTION: A ruthenium-aluminum perovskite-based phosphor is represented by chemical formula 1: (Lu_(1-a-b)A_aB_b)D_dO_3 where A is one or two more elements selected from Sc, Y, La, and Gd; B is one or two more selected from Ce, Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, and Yb; D is one or a mixture of two or more selected from Al, B, Ga, And In; and , 0 <= a <= 0.6, 0.001 <= b <= 0.5, 0.5<= d <= 1.5.

Description

A lutetium-aluminium perovskite phosphor materials and their applications for white-light-emitting device

The present invention relates to a blue light excitation ruthenium-aluminum perovskite-based phosphor and a white light emitting diode using the same, and more particularly, to a phosphor containing ruthenium and aluminum as a basic structure based on a perovskite structure. Since the wavelength ranges from 380 to 470 nm and the emission wavelength is maintained in the range of 510 to 560 nm, it is possible to excite from blue or ultraviolet light, so that the green light and yellow light can be expressed in the blue light and yellow light. The present invention relates to a phosphor-based phosphor and a white light emitting device using the same.

Currently, in order to manufacture light emitting diodes such as blue, green, and red, different substrates such as InGaN, GaN, GaAs, and ZnO must be manufactured. This manufacturing process requires the use of different semiconductor thin films. It has a problem of high investment cost and high manufacturing cost. Therefore, if a light emitting diode with blue, red, and green light emitting diodes can be manufactured using the same semiconductor thin film, the manufacturing process and the investment cost can be drastically reduced since the process is simplified.

In addition, a white light emitting diode, which is spotlighted as a back light source for a liquid crystal display such as lighting, a notebook, a mobile phone, and the like, is manufactured by combining a YAG: Ce phosphor emitting yellow (560 nm) to a blue light emitting diode. Since white light emitting diodes utilizing blue light emitting diodes have wavelengths of 450 to 470 nm as excitation energy sources, there are many problems with suitable fluorescent materials. That is, using a blue light emitting diode having a wavelength of 450 ~ 470 nm is difficult to implement only a white light emitting diode using YAG: Ce. Attempts have been made to use a mixture of yellow, red, green and orange phosphors to solve these problems, and therefore, development of red and green phosphors as well as yellow is urgent.

An object of the present invention is to provide a new green phosphor that can use an excitation wavelength of 450 ~ 470 nm band in order to solve the problems of the background art described above.

It is also an object of the present invention to provide a white light emitting device in which a green phosphor is mixed with other phosphors.

The ruthenium-aluminum perovskite-based phosphor of the present invention for solving the above problems is represented by the following formula (1).

[Formula 1]

(Lu _{1 -a- b} A _a B _b ) D _d O ₃

(Wherein A is one or two or more elements selected from Sc, Y, La, and Gd, and B is one selected from Ce, Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, and Yb, which are lanthanum-based elements) Or 2 or more elements, D is Al alone or a mixture of Al and one or more elements selected from B, Ga, and In, 0 ≦ a ≦ 0.6, 0.001 ≦ b ≦ 0.5, and 0.5 ≦ d ≦ 1.5 Indicates)

Preferably, the phosphor is characterized in that the excitation wavelength is 380 ~ 470 nm, the emission wavelength is in the range of 510 ~ 560 nm.

In addition, the white light emitting device of the present invention, the excitation light source in the range of 380 ~ 410 nm or 430 ~ 480 nm; And a mixed phosphor obtained by mixing the phosphor of claim 1 with at least one phosphor selected from a green yellow phosphor, an orange phosphor, and a red phosphor; .

Preferably, the green yellow phosphor is at least one of (Lu, Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce-based phosphor and (Sr, Ba) ₂ SiO ₄ : Eu-based phosphor.

Preferably, the orange phosphor is _{(Sr, Ba) Si 2 O} 2 N 2: Eu 2 + phosphor and a line _{(Sr, Ba) 3 SiO 5} : Eu ^{2 +} of at least any one series phosphors.

Preferably, the red phosphor is at least one of (Sr, Ba) ₂ Si ₅ N ₈ : Eu-based phosphor and CaAlSiN: Eu-based phosphor.

The phosphor of the present invention can be selectively used from the green region to the yellow color, and can be selectively used for the light emitting diode for blue (450 to 470 nm) or the light emitting diode for ultraviolet light (380 to 410 nm), and is excited and green from this. It is easy to apply to blue light emitting diode and active light emitting liquid crystal display because of excellent white expression and luminous efficiency by mixing and using alone and orange.

1 shows an emission spectrum obtained by exciting the A (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor prepared in Example 1 of the present invention with an excitation light of 450 nm blue light.
2 is manufactured by a second embodiment according to the _invention shows the (Lu _{1 a} Ce _a) excites the phosphor according to the change of the AlO _three phosphors a with an excitation light of 450 nm blue shift in the emission intensity gained.
3 shows an emission spectrum obtained by exciting the phosphor according to the synthesis temperature of the (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor prepared in Example 3 according to the present invention with an excitation light of 450 nm blue light.
Figure 4 shows the excitation spectra of (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor prepared in Example 1 according to the present invention.
Figure 5 shows an emission spectrum obtained by exciting the phosphor of (Y Lu _{0 .65 0 .05 0 .3} Ce) AlO ₃ prepared in Example 4 according to the present invention with an excitation light of 450 nm blue light.
6 shows an emission spectrum obtained by exciting the phosphor according to the addition of the flux (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor prepared in Example 5 according to the present invention with an excitation light of 450 nm blue light.
7 is manufactured by the seventh embodiment according to the present invention (Lu _{0 .95 0 .05} Ce) AlO ₃ and commercial phosphor _{(Sr 2 .93 Eu 0 .07)} SiO mixed phosphor of the phosphor _5, and, (Lu _{0. 95} Ce _{0 .05)} shows a phosphor ₃ AlO and commercial (Lu _2.94 Ce _0.06) emission spectrum obtained by exciting the phosphor mixture of the Al ₅ O ₁₂ phosphor with an excitation light of 450 nm blue light.

The present invention is characterized by a ruthenium-aluminum perovskite-based phosphor represented by the following formula (1).

[Formula 1]

(Lu _{1 -a- b} A _a B _b ) D _d O ₃

In Formula 1, A is one or two or more elements selected from Sc, Y, La, and Gd, and B is a lanthanum-based element Ce, Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, and Yb One or two or more elements selected from among D is Al alone or a mixture of Al and one or two or more elements selected from among B, Ga and In, 0 ≦ a ≦ 0.6, 0.001 ≦ b ≦ 0.5, and 0.5 ≦ d ≤ 1.5.

When the content of a exceeds 0.6 mol, the luminance decreases due to structural nonuniformity.

b is a content range of the active agent, using 0.001 to 0.5 mol, preferably 0.001 to 0.3 mol. If it is less than 0.001 mole, it will not become an amount sufficient to function as an active agent, and if it exceeds 0.5 mole, the brightness will fall due to concentration quenching phenomenon.

If the content of d is less than 0.5 mole, the crystallinity of the perovskite structure is inferior, and if it exceeds 1.5 moles, unreacted aluminum oxide or gallium oxide remains.

The present invention is a ruthenium-aluminum perovskite-based fluorescent material which is excited in the range of 380 to 410 nm or 430 to 480 nm to express green light and yellow light.

Generally, sialon or silicate-based phosphors are used locally as phosphors excited at blue wavelengths of 450 to 470 nm in order to express green light. However, there is a problem of patent infringement. It's urgent.

Therefore, the present invention has a perovskite structure and has a excitation band in the blue wavelength range of 450 ~ 470 nm while containing ruthenium and aluminum to reduce the synthesis temperature and evenly distributed particles in the blue wavelength range of 450 ~ 470 nm It emits light efficiently and is excited in the blue or ultraviolet wavelength range, and green and yellow light can be expressed.

Hereinafter, a method of manufacturing the ruthenium-aluminum perovskite-based phosphor of the present invention will be described in detail.

First, as shown in Formula 1, a precursor compound is prepared by weighing and mixing a precursor compound of a raw material element constituting the phosphor. The precursor compound of the raw material is generally used in the art, halides, oxides, nitrides, sulfides, chlorides and the like may be used, but in the present invention, it is preferable to use an oxide that is stable in air.

The mixing method is generally used in the art, and is not particularly limited, but in the present invention, mixing is performed using agate induction or ball mill. Subsequently, the mixture is placed in an oven and dried at 100 to 150 ° C. for 15 to 30 hours. If the drying temperature is less than 100 ° C., efficient drying does not occur. Occurs.

Next, the mixed precursor is heat-treated under a mixed gas atmosphere of nitrogen and hydrogen to prepare a ruthenium-aluminum perovskite-based phosphor represented by Chemical Formula 1. In this case, it is common to use an electric furnace in a high purity alumina boat for heat treatment. Temperature during heat treatment is preferably performed in the range of 1200 ~ 1800 ℃, preferably 1400 ~ 1700 ℃ and is carried out for 1 to 48 hours, when the heat treatment temperature is less than 1200 ℃ do not emit light because no crystal phase is formed 1800 ℃ In the case of exceeding, it is preferable to keep the above range because the sample is melted to obtain the correct powder and the luminous efficiency is lowered.

At this time, the hydrogen gas in the mixed gas is introduced to react with the precursor to reduce the activator and form a perovskite phase, and it is preferable to use nitrogen and hydrogen gas in a 75 to 98: 2 to 25 volume ratio. When the volume ratio of nitrogen exceeds the above range, the reduction of the activator is not performed well, so that light of a desired color cannot be expressed. When the volume ratio of hydrogen exceeds the above range, hydrogen gas reacts with external oxygen and explodes. As a problem arises, it is desirable to maintain the volume ratio.

The photoluminescence (PL) of the powder obtained above was measured with an excitation wavelength of 450 nm, and a spectrum having a main peak in the green to yellow region (510 nm to 560 nm) was shown.

The phosphor of the present invention prepared above has a ruthenium-aluminum perovskite-based structure, and green and yellow phosphors doped with lanthanum-based elements such as cerium as an activator are applied to a blue light emitting diode and an active light emitting liquid crystal display. It has very high luminous efficiency.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Of course, the claims of the present invention are not limited to the examples.

Example  One: ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor

Ruthenium oxide (Lu ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ) and cerium oxide (CeO ₂ ) as a raw material was weighed to each predetermined ratio according to the desired composition. The mixture was sufficiently mixed to achieve a uniform composition using a ball milling or agate induction mixer under 5 mL of acetone solvent for effective mixing. The mixture was then placed in an oven and dried at 120 ° C. for 24 hours. The dry mixture was placed in a high-purity alumina boat and heat-treated at 1700 ° C. under a reducing atmosphere in which a mixed gas of 25% by volume of hydrogen and 75% by volume of nitrogen was supplied for 0.3 hours / hour using an electric furnace (Lu _0.95 Ce _0.05 ) AlO ₃ phosphors .

The emission spectrum of the phosphor obtained therefrom was measured and shown in FIG. 1. According to the drawings, it was confirmed that the central wavelength is green (the main peak is about 510 nm).

Example  2: ( Lu _{One - b} Ce _b ) AlO ₃  Phosphor

In the same manner as in Example 1, by adjusting the amount of cerium oxide (CeO ₂ ) to change the content of b to 0.005 to 1 molar range to prepare a (Lu _{1 - b} Ce _b ) AlO ₃ phosphor.

As a result of measuring the emission spectrum of the phosphor obtained therefrom, the result is shown in FIG. 2, and as the amount of Ce increases, the center wavelength of green (main peak is about 510 nm) increases without change and the intensity decreases again. Could.

Example  3: ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor

In the same manner as in Example 1, but using ruthenium oxide (Lu ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), cerium oxide (CeO ₂ ), the synthesis temperature at the time of synthesis from 1300 to 1700 It was also changed to (Lu _{0 .95 0 .05} Ce) AlO ₃ was prepared in the phosphor.

The emission spectrum of the phosphor obtained therefrom was measured and the results are shown in FIG. 3. As a result, the emission intensity was gradually increased as the synthesis temperature was increased.

Example  4 : ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor

In the same manner as in Example 1, ruthenium oxide (Lu ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), cerium oxide (CeO ₂ ) was used, the synthesis temperature in the synthesis at 1500 degrees ( Lu _{0 .95} Ce _{0 .05)} to prepare a phosphor AlO _3.

The excitation spectrum of the phosphor obtained therefrom was measured and the results are shown in FIG. 4.

Example  5: ( Lu _{0 .75} Y _{0 .2} Ce _{0 .05} ) AlO ₃  Phosphor

In the same manner as in Example 1, ruthenium oxide (Lu ₂ O ₃ ), yttrium oxide (Y ₂ O ₃ ), aluminum oxide (Al ₂ O ₃ ), cerium oxide (CeO ₂ ) was used, the yttrium By adjusting the amount of oxide (Y ₂ O ₃ ) (Lu _0.75 Y _0.2 Ce _0.05 ) AlO ₃ To prepare a phosphor.

The emission spectrum of the phosphor obtained therefrom was measured and the results are shown in FIG. 5. As a result, the emission band shifted to a longer wavelength as the amount of Y added increased.

Example  6: ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor

The synthesis was carried out as Example 1, the base potassium oxide (Lu ₂ O _3), aluminum oxide (Al ₂ O _3), was used as a cerium oxide (CeO _2), the (Lu _{0 .95} Ce _{0 .05)} Ammonium fluoride (NH ₄ ) was used as flux in the preparation of AlO ₃ phosphors.

The emission spectrum of the phosphor obtained therefrom was measured, and the results are shown in FIG. 6. As a result, it was confirmed that the use of ammonium fluoride (NH ₄ ) increased the emission intensity of about 10% compared to the case without use.

Example  7: ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor and ( Sr _{2 .93} Eu _{0 .07} ) SiO ₅  Phosphor mixing

Were mixed at a 1: Example 1 a (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor and one of the well-known commercially available orange, (Sr _2.93 Eu _0.07) SiO ₅ fluorescent material in a mass ratio to the prior made.

The mixed phosphor obtained therefrom was mixed with silicon at a mass ratio of 1: 0.05 on a blue light emitting diode, and the emission spectrum of the resulting white light emitting diode was measured. The result is shown in FIG. 7, and the color temperature was 4500. A high quality white color of K and color rendering index 80 could be confirmed.

Example  8 : ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor and ( Lu _{2 .94} Ce _{0 .06} ) Al ₅ O ₁₂  Phosphor mixing

Were mixed at a 1: Example 1 a (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor and of the commercial green-yellow well known in the art _{(Lu 2.94 Ce 0.06) Al 5} O 1 to ₁₂ in a mass ratio of the phosphor produced with.

A mixed fluorescent material obtained therefrom to silrikonwa mass ratio 1: and packaged in a light-emitting blue color to the resin mixture diode to 0.05, by measuring the emission spectrum of the white LED obtained as a result shown in Fig. 7 and the results Results, (Lu ₀ as compared to _.95 Ce _{0 .05)} when used as a single phosphor AlO _3, the color temperature is lower, the color rendering property could be confirmed to become more excellent. This (Lu _{2 .94} Ce _{0 .06)} in green from the Al ₅ O ₁₂ phosphor due to the effect of the luminescent color to yellow.

Example  9: ( Lu _{0 .95} Ce _{0 .05} ) AlO ₃  Phosphor and red Sr ₂ Si ₅ N ₈ : Eu  Phosphor mixing

Were mixed at a 0.5: Example 1 a (Lu _{0 .95 0 .05} Ce) AlO ₃ phosphor and a well-known commercial red Sr2Si5N8 the prior made of: the first fluorescent material in a mass ratio of Eu.

The resin obtained by mixing the mixed phosphor obtained at 1: 0.05 in a mass ratio of silicon was packaged on a blue light emitting diode, and the emission spectrum of the resulting white light emitting diode was measured. As a result, the color temperature (3800 K) was lowered and color rendering ( 85) was confirmed to be better. This is due to 620 nm red emission from the red Sr ₂ Si ₅ N ₈ : Eu phosphor.

None

Claims (6)

A ruthenium-aluminum-based perovskite-based phosphor, characterized in that represented by the following formula (1).
[Formula 1]
(Lu _{1 -a- b} A _a B _b ) D _d O ₃
(Wherein A is one or two or more elements selected from Sc, Y, La, and Gd, and B is one selected from Ce, Pr, Nd, Sm, Eu, Dy, Ho, Er, Tm, and Yb, which are lanthanum-based elements) Or 2 or more elements, D is Al alone or a mixture of Al and one or more elements selected from B, Ga, and In, 0 ≦ a ≦ 0.6, 0.001 ≦ b ≦ 0.5, and 0.5 ≦ d ≦ 1.5 Indicates) The method of claim 1,
The phosphor has an excitation wavelength of 380 to 470 nm, and a light emitting wavelength of 510 to 560 nm in the ruthenium-aluminum-based perovskite-based phosphor. Excitation light sources in the range of 380-410 nm or 430-480 nm; And
A mixed phosphor that is excited by the excitation light source and mixed the phosphor of claim 1 with one or two or more phosphors selected from a green yellow phosphor, an orange phosphor, and a red phosphor;
White light emitting device comprising a. The method of claim 3, wherein
The green-yellow phosphor is at least one of (Lu, Y, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce-based phosphor and (Sr, Ba) ₂ SiO ₄ : Eu-based phosphor. The method of claim 3, wherein
The orange phosphor is at least one of (Sr, Ba) Si ₂ O ₂ N ₂ : Eu ^{2 +} -based phosphor and (Sr, Ba) ₃ SiO ₅ : Eu ²⁺ -based phosphor. The method of claim 3, wherein
The red phosphor is at least one of (Sr, Ba) ₂ Si ₅ N ₈ : Eu-based phosphor and CaAlSiN: Eu-based phosphor.

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