JP2014095029A - Ca-Sc(-Si)-O-BASED FLUOPHOR - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve luminous characteristics of CaScSiO:Ceby using inexpensive raw materials.SOLUTION: The Ca-Sc(-Si)-O-based fluophor has a composition represented by the general formula: (MCe)(MCu)MO, where Mis divalent metal element containing at least Ca, Mis a trivalent metal element containing at least Sc, Mis a tetravalent metal element containing at least Si, 0.01≤x≤0.10, 0.001≤y≤0.100, a, b, d are positive numbers excluding 0, and c is 0 or a positive number. The Ca-Sc(-Si)-O-based fluophor is obtained by co-activation of Cuin addition to Ceand has improved luminous characteristics by using inexpensive raw materials.

Description

  The present invention relates to a Ca—Sc (—Si) —O-based phosphor.

  Phosphors that emit blue light and emit yellow light are attracting attention as phosphors for LEDs.

As a phosphor that emits blue light and emits yellow light, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce ³⁺ (CSS: Ce) is known, but it has a problem of low emission luminance.

As a conventional method for improving the light emission characteristics of CSS: Ce, a method in which Mg ²⁺ is dissolved in Sc sites in the host crystal is known. However, there is a problem that Mg oxide and carbonate which are raw materials of Mg ²⁺ are expensive.

JP 2012-87232 A

The present _{invention, Ca 3 Sc 2 Si 3 O} 12 using inexpensive raw materials: an object to improve the emission characteristics of ^{Ce 3+.}

The inventors of the present invention have made extensive studies to solve the above-mentioned problems. As a result, Ca—Sc (—Si) — is used, using Cu ₂ O, which is cheaper than Mg oxide and carbonate, which are raw materials for Mg ^2+. by co-activator of Cu ⁺ with Ce ³⁺ to O based phosphor, it found that it is possible to improve the light emission characteristics, and conceived the present invention.

That is, the Ca—Sc (—Si) —O-based phosphor according to claim 1 of the present invention has a general formula: general formula: (M ¹ _1-y Ce _y ) _a (M ² _1-x Cu _x ) _b M ³ _c O _d (M ¹ is a divalent metal element containing at least Ca, M ² is a trivalent metal element containing at least Sc, M ³ is a tetravalent metal element containing at least Si, and 0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100, a, b and d are positive numbers not including 0, and c is 0 or a positive number) To do.

The Ca—Sc (—Si) —O-based phosphor according to claim 2 of the present invention has a general formula: (Ca _1−y Ce _y ) ₃ (Sc _1−x Cu _x ) ₂ Si ₃ O ₁₂ (0. 01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100).

The Ca—Sc (—Si) —O-based phosphor according to claim 3 of the present invention has a general formula: (Ca _1−y Ce _y ) (Sc _1−x Cu _x ) ₂ O ₄ (0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100).

  The Ca—Sc (—Si) —O-based phosphor according to claim 4 of the present invention is y = 0.01 in claim 2 or 3.

The Ca—Sc (—Si) —O phosphor of the present invention is obtained by co-activating Cu ⁺ together with Ce ^{3+ in} a Ca—Sc (—Si) —O phosphor, and using an inexpensive raw material. The light emission characteristics are improved.

The upper row is a photograph of (Ca _0.99 Ce _0.01 ) ₃ (Sc _1-x Cu _x ) ₂ Si ₃ O ₁₂ , with x = 0, 0.01, 0.03, 0.10 in order from the left. is there. The lower row is a photograph showing the state of light emission when irradiated with ultraviolet rays having a wavelength of 302 nm. A _{(Ca 0.99 Ce 0.01) 3 (} Sc 1-x Cu x) 2 Si 3 O 12, x = X-ray powder diffraction pattern of 0,0.01. It is an excitation spectrum and an emission spectrum of (Ca _0.99 Ce _0.01 ) ₃ (Sc _1-x Cu _x ) ₂ Si ₃ O ₁₂ , x = 0, 0.01, 0.03, 0.10. The upper row is a photograph of (Ca _0.99 Ce _0.01 ) (Sc _1-x Cu _x ) ₂ O ₄ , with x = 0, 0.01, 0.03, 0.10 in order from the left. The lower row is a photograph showing the state of light emission when each is irradiated with ultraviolet rays having a wavelength of 254 nm. _(Ca 0.99 _{Ce 0.01)} is a powder X-ray diffraction pattern of _{(Sc 1-x Cu x)} 2 O 4, x = 0,0.01,0.03,0.10. It is an excitation spectrum and an emission spectrum of (Ca _0.99 Ce _0.01 ) (Sc _1-x Cu _x ) ₂ O ₄ , x = 0, 0.01, 0.03, 0.10.

The Ca—Sc (—Si) —O-based phosphor of the present invention has a general formula: General formula: (M ¹ _1-y Ce _y ) _a (M ² _1-x Cu _x ) _b M ³ _c O _d (M ¹ is a divalent metal element containing at least Ca, M ² is a trivalent metal element containing at least Sc, M ³ is a tetravalent metal element containing at least Si, and 0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100, a, b, d is a positive number not including 0, and c is 0 or a positive number), and a Ca—Sc (—Si) —O system A phosphor is obtained by co-activating Cu ^{3 +} together with Ce ^{3 +} .

By co-activating Cu ⁺ , the light emission characteristics are improved, the emission spectrum and the visibility curve are largely overlapped, and a high-luminance phosphor can be obtained.

Further, since Cu ₂ O as a raw material for Cu ⁺ is cheaper than Mg oxide and carbonate as raw materials for Mg ²⁺ , it is less expensive than Ca—Sc compared with the prior art that coactivates Mg ^2+. A (—Si) —O-based phosphor can be provided. Furthermore, by replacing expensive Sc with inexpensive Cu, a Ca—Sc (—Si) —O-based phosphor can be provided at low cost.

M ¹ is a divalent metal elements including at least Ca, in addition to Mg of Ca as ^{M 1, Zn, Sr, Cd} , may contain Ba. As the green phosphor, it is preferable more than 70 mole% of elements M ¹ is Ca.

Further, ^{M 2} is a trivalent metal element including at least Sc, in addition to Al and Sc as ^{M 2, Ga, Y, In} , La, Gd, Yb, may contain Lu. In order to increase the emission intensity, 70 mol% or more of the element of M ² is preferably Sc.

M ³ is a tetravalent metal element containing at least Si. When M ³ is contained, Ti, Ge, Zr, Sn, and Hf may be included in addition to Si. Preferably, at least 70 mole% of the elements of ^{M 3} is is Si.

  Further, from the viewpoint of emission intensity, 0.01 ≦ x ≦ 0.10 and 0.001 ≦ y ≦ 0.100 are preferable.

Examples of the Ca—Sc (—Si) —O-based phosphor of the present invention include a general formula: (Ca _1−y Ce _y ) ₃ (Sc _1−x Cu _x ) ₂ Si ₃ O ₁₂ (0.01 ≦ Ca—Sc—Si—O-based phosphors having a composition represented by x ≦ 0.10, 0.001 ≦ y ≦ 0.100), a general formula: (Ca _1-y Ce _y ) (Sc _1-x Examples thereof include Ca—Sc—O based phosphors having a composition represented by Cu _x ) ₂ O ₄ (0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100).

  The Ca—Sc (—Si) —O-based phosphor of the present invention is obtained by weighing carbonate and oxide in accordance with the stoichiometric ratio, and firing the mixture in a reducing atmosphere. Moreover, the Ca—Sc (—Si) —O-based phosphor of the present invention can be produced without requiring a special synthesis apparatus.

The powder raw materials of CaCO ₃ , Sc ₂ O ₃ , SiO ₂ , CeO ₂ , and Cu ₂ O were weighed according to the stoichiometric ratio, and wet mixed using acetone. Using an electric furnace, firing was performed at 1500 ° C. for 3 hours in a reducing atmosphere. The obtained powder was pulverized and then evaluated using a powder X-ray diffractometer and a fluorescence spectrophotometer.

A photograph of the synthesized phosphor is shown in FIG. The upper row is a photograph of (Ca _0.99 Ce _0.01 ) ₃ (Sc _1-x Cu _x ) ₂ Si ₃ O ₁₂ , with x = 0, 0.01, 0.03, 0.10 in order from the left. is there. The lower row is a photograph showing the state of light emission when irradiated with ultraviolet rays having a wavelength of 302 nm. A uniform phosphor was obtained, and showed strong light emission when x = 0.01, 0.03, 0.10. The body color of Ca ₃ Sc ₂ Si ₃ O ₁₂ (CSS) that does not activate Cu ⁺ is green, whereas the body color of CSS that activates Cu ⁺ is yellow.

  FIG. 2 shows a powder X-ray diffraction pattern of the obtained powder. Since the CSS simulation pattern matched the pattern, it was confirmed that the CSS was generated.

FIG. 3 shows an excitation spectrum and an emission spectrum. The short wavelength side is the excitation spectrum and the long wavelength side is the emission spectrum. It had strong absorption in the vicinity of 450 nm, which is the light emitting region of the blue LED. The CSS in which Cu ⁺ was activated did not decrease the emission intensity, increased the emission intensity at 550 nm, and good fluorescence characteristics were obtained.

The powder raw materials of CaCO ₃ , Sc ₂ O ₃ , CeO ₂ , and Cu ₂ O were weighed according to the stoichiometric ratio, and wet-mixed using acetone. Using an electric furnace, firing was performed at 1500 ° C. for 3 hours in a reducing atmosphere. The obtained powder was pulverized and then evaluated using a powder X-ray diffractometer and a fluorescence spectrophotometer.

A photograph of the synthesized phosphor is shown in FIG. The upper row is a photograph of (Ca _0.99 Ce _0.01 ) (Sc _1-x Cu _x ) ₂ O ₄ , with x = 0, 0.01, 0.03, 0.10 in order from the left. The lower row is a photograph showing the state of light emission when each is irradiated with ultraviolet rays having a wavelength of 254 nm. The body color was yellow-green, and uniform green emission was seen when irradiated with ultraviolet rays.

FIG. 5 shows a powder X-ray diffraction pattern of the obtained powder. Since the simulation pattern of CaSc ₂ O ₄ (CSO) matched the pattern, it was confirmed that CSO was generated. The peak of Cu contained as _Sc 2 _{O 3} and impurities of the raw materials was confirmed.

  FIG. 6 shows an excitation spectrum and an emission spectrum. The short wavelength side is the excitation spectrum and the long wavelength side is the emission spectrum. It had strong absorption in the blue region near 450 nm and strong emission in the green region of 510 nm.

Claims (4)

General formula: (M ¹ _1-y Ce _y ) _a (M ² _1-x Cu _x ) _b M ³ _c O _d (M ¹ is a divalent metal element containing at least Ca, M ² is 3 containing at least Sc A valent metal element, M ³ is a tetravalent metal element containing at least Si, and 0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100, a, b, d do not include 0. A Ca—Sc (—Si) —O-based phosphor having a composition represented by a positive number, c being 0 or a positive number). General formula: (Ca _1-y Ce _y ) ₃ (Sc _1-x Cu _x ) ₂ Si ₃ O ₁₂ (0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100) A Ca—Sc (—Si) —O-based phosphor having a composition. It consists of a composition represented by the general formula: (Ca _1-y Ce _y ) (Sc _1-x Cu _x ) ₂ O ₄ (0.01 ≦ x ≦ 0.10, 0.001 ≦ y ≦ 0.100). Ca-Sc (-Si) -O-based phosphor. The Ca-Sc (-Si) -O-based phosphor according to claim 2 or 3, wherein y = 0.01.