JP7235965B2 - Boron nitride phosphor and manufacturing method thereof - Google Patents

Description

TECHNICAL FIELD The present invention relates to a boron nitride phosphor and a manufacturing method thereof.

By combining an excitation light source such as a light emitting diode (hereinafter also referred to as "LED") or a laser diode (hereinafter also referred to as "LD") and a phosphor, a white, 2. Description of the Related Art Various light-emitting devices that emit light in the color of an incandescent bulb or the like have been developed. These light-emitting devices are used in a wide range of fields such as illumination, vehicle-mounted, backlight for liquid crystal display devices, displays, illumination, and projectors.

As such a light-emitting device, for example, Patent Document 1 describes a combination of an excitation light source that emits light in a wavelength range of 250 nm or more and 400 nm or less, and a phosphor that absorbs at least part of the light and emits light. A light emitting device is disclosed that emits a mixed color light of a system. As a phosphor used in such a light emitting device, for example, M ₂ SiO ₄ :Eu ²⁺ (wherein M is at least a divalent metal selected from the group consisting of Sr, Ca, Ba, Mg, Zn and Cd) is one.) is known.

Japanese translation of PCT publication No. 2008-509552

Development of phosphors that can provide various emission spectra depending on the application, can be emitted by excitation light in a wide range of wavelengths, and can satisfy the requirements for emission characteristics and reliability as phosphors used in light-emitting devices. is desired.
Accordingly, an object of one aspect of the present invention is to provide a boron nitride phosphor, a light-emitting device, and a method for manufacturing the same that have the potential to satisfy such demands.

Means for solving the above problems include the following aspects.

A first aspect of the present invention has at least one emission peak wavelength in the range of 480 nm or more and less than 650 nm when excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, and from an alkaline earth metal element containing at least one element A selected from the group consisting of nitrogen and boron, and optionally at least one element M1 selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb , a boron nitride phosphor.

A second aspect of the present invention has at least one emission peak wavelength in the range of 480 nm or more and less than 650 nm when excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, and from an alkaline earth metal element A boron nitride phosphor containing at least one element A selected from the group consisting of nitrogen and boron.

A third aspect of the present invention is a light-emitting device including the boron nitride phosphor and an excitation light source.

A fourth aspect of the present invention is a hydride or nitride containing at least one element A selected from the group consisting of alkaline earth metal elements, boron nitride, and optionally Tb, Sm, Pr, Ce , a compound containing at least one element M1 selected from the group consisting of Mn and Yb, preparing a mixture, and heat-treating the mixture at a pressure in the range of 10 atmospheres or less. manufacturing method.

In a fifth aspect of the present invention, a mixture is prepared by mixing a hydride or nitride containing at least one element A selected from the group consisting of alkaline earth metal elements and boron nitride, and the mixture is A method for producing a boron nitride phosphor including a step of heat-treating at a pressure in the range of 10 atmospheres or less.

ADVANTAGE OF THE INVENTION According to one aspect of the present invention, it is possible to provide a boron nitride phosphor, a light-emitting device, and a method for manufacturing the same, which emit light having various emission spectra by excitation light in a relatively wide wavelength range.

FIG. 1 is a diagram showing an emission spectrum of a boron nitride phosphor according to Example 1. FIG. FIG. 2 is a diagram showing an emission spectrum of a boron nitride phosphor according to Example 2. FIG. FIG. 3 is a diagram showing an emission spectrum of a boron nitride phosphor according to Example 3. FIG. 4 is a diagram showing an emission spectrum of a boron nitride phosphor according to Example 4. FIG. 5 is a diagram showing an emission spectrum of a boron nitride phosphor according to Example 5. FIG. 6 is a diagram showing an emission spectrum of a boron nitride phosphor according to Example 6. FIG. FIG. 7 is a diagram showing excitation spectra of boron nitride phosphors according to Examples 4 to 6. FIG. FIG. 8 is a diagram showing the relative emission energy (%) in the temperature range from 25° C. (room temperature) to 150° C. for the boron nitride phosphor according to Example 1 and the orthosilicate phosphor of the reference example.

Hereinafter, the boron nitride phosphor, the light emitting device, and the method for manufacturing the boron nitride phosphor according to the present invention will be described. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following boron nitride phosphor, light emitting device, and method for manufacturing the boron nitride phosphor. The relationship between the color name and chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, etc. conform to JIS Z8110.

Boron Nitride Phosphor The boron nitride phosphor according to the present invention is excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less and has at least one emission peak wavelength in the range of 480 nm or more and less than 650 nm. At least one element A selected from the group consisting of earth metal elements, nitrogen and boron, and optionally at least one element selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb and M1.

The boron nitride phosphor is excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, has at least one emission peak wavelength in the range of 480 nm or more and less than 650 nm, and is selected from the group consisting of alkaline earth metal elements. It contains at least one selected element A, nitrogen and boron.

The boron nitride phosphor may contain a composition represented by the following formula (I).
A ₃ B ₂ N ₄ : M1 _x (I)
(In formula (I), A is at least one element selected from the group consisting of alkaline earth metal elements, and M1 is selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb. At least one element, and x is a number that satisfies 0≤x≤0.10.)

The boron nitride phosphor may contain a composition represented by the following formula (II).
_{A3B2N4 ( II} )
(In formula (II), A is at least one element selected from the group consisting of alkaline earth metal elements.)

Examples of light-emitting elements having an emission peak wavelength in the near-ultraviolet wavelength range include semiconductor lasers. Phosphors capable of wavelength conversion with excitation light from a light-emitting element having an emission peak wavelength in the range of 250 nm or more and 460 nm or less including the near-ultraviolet region are desired. The boron nitride phosphor according to the first embodiment of the present invention has an emission peak in the green to orange region of 480 nm or more and less than 650 nm by excitation light from a light emitting element having an emission peak wavelength in the range of 250 nm or more and 460 nm or less. have a wavelength. The excitation light of the light-emitting device preferably has an emission peak wavelength in the range of 250 nm or more and 400 nm or less, more preferably 250 nm or more and 380 nm or less, and particularly preferably 250 nm or more and 370 nm or less. It has an emission peak wavelength within the range.

The element A contained in the boron nitride phosphor is at least one element selected from the group consisting of alkaline earth metal elements. The element A is preferably at least one element selected from the group consisting of Mg, Ca, Sr and Ba, more preferably selected from the group consisting of Ca, Sr and Ba, from the viewpoint of luminous efficiency and reliability. It contains at least one element, more preferably at least one element selected from Ca and Ba, and even more preferably Ca.

The boron nitride phosphor exhibits an emission spectrum resulting from at least one host emission by excitation light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less. The element M1 contained in the boron nitride phosphor and the element M1 in the composition represented by the formula (I) are activating elements contained in the matrix, and the boron nitride phosphor is a phosphor exhibiting matrix emission. Therefore, light can be emitted even when the element M1, which is an activating element, is not included. The boron nitride phosphor may not contain the element M1, which is an activating element. The boron nitride phosphor that does not contain the element M1 preferably has a composition represented by the formula (II). The boron nitride phosphor may contain an activating element represented by the element M1. When the boron nitride phosphor contains the element M1, which is an activating element, it absorbs excitation light in a wide range of wavelengths, and emits light having various emission spectra due to the activating element, which is emitted by the boron nitride phosphor. You can change the color tone of the light. Element M1 is at least one element selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb, preferably at least one element selected from the group consisting of Tb, Sm, Pr, Ce and Mn. more preferably at least one element selected from the group consisting of Tb, Sm, Pr and Mn, and even more preferably at least one element selected from the group consisting of Tb, Sm and Pr. The element M1 may be at least one element selected from the group consisting of Tb, Sm and Yb, or at least one element selected from Tb and Yb. Element M1 excludes Eu. When excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, europium may become a killer element that inhibits the luminescence of the boron nitride compound. In the composition represented by the formula (I), the variable x represents the molar ratio of the element M1 which is the activating element of the boron nitride phosphor, and the variable x representing the molar ratio of the element M1 is 0. good. In the composition represented by the formula (I), the variable x is 0 or more and 0.10 or less (0 ≤ x ≤ 0.10), preferably 0 or more and 0, from the viewpoint of color tone change depending on the type of light source and reliability. 0.08 or less (0 ≤ x ≤ 0.08), more preferably 0 or more and 0.05 or less (0 ≤ x ≤ 0.05), still more preferably 0 or more and 0.03 or less (0 ≤ x ≤ 0.03) is.

The boron nitride phosphor is excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less and has at least one emission peak wavelength in the range of 480 nm or more and less than 550 nm, and the element A contains Ca. is preferred. When the boron nitride phosphor contains the element M1, the element M1 is preferably at least one element selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb. In the boron nitride phosphor containing the composition represented by the formula (I), the element A contains Ca, and the element M1 is at least one selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb. It is preferably an element, and x is a number that satisfies 0≦x≦0.03. The boron nitride phosphor may be excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less and have two emission peak wavelengths in the range of 480 nm or more and less than 550 nm. The boron nitride phosphor may be excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, and may have an emission peak wavelength in a range exceeding 550 nm due to the element M1. When the boron nitride phosphor has an emission peak in the range over 550 nm, the emission intensity of the emission peak in the range over 550 nm is lower than the emission intensity of the emission peak in the range of 480 nm or more and less than 550 nm.

Light Emitting Device A light emitting device according to the present invention includes the boron nitride phosphor according to the present invention and an excitation light source. The excitation light source is preferably a light emitting diode (LED) or semiconductor laser (LD). Light-emitting diodes (LEDs) include, for example, nitride-based semiconductors (In _X Al _Y Ga _1-XY N, X≧0, Y≧0, X+Y≦1). By using a light-emitting diode using a nitride-based semiconductor as an excitation light source, it is possible to obtain a stable light-emitting device with high efficiency, high output linearity with respect to input, and resistance to mechanical impact. Examples of semiconductor lasers include Nd:YAG lasers, KrF excimer lasers, ArF excimer lasers, and the like. A light-emitting device in which boron nitride and an LED are combined can be used in fields such as lighting and standard light sources. A light-emitting device that combines a boron nitride phosphor and an LD can be used in fields such as lighting and projectors.

Method for producing boron nitride phosphor A method for producing a boron nitride phosphor according to the present invention comprises a hydride or nitride containing at least one element A selected from the group consisting of alkaline earth metal elements, boron nitride, A step of preparing a mixture optionally mixed with a compound containing at least one element M1 selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb, and heat-treating the mixture at a pressure in the range of 10 atmospheres or less. including. The heat treatment is preferably performed at a pressure in the range of 1 atmosphere to 10 atmospheres. As the compound containing the element M1, the element M1 may be at least one element selected from the group consisting of Tb, Sm and Yb. Element M1 may be at least one element selected from Tb and Yb.

In the method for producing a boron nitride phosphor according to the present invention, a hydride or nitride containing at least one element A selected from the group consisting of alkaline earth metal elements and a compound containing boron nitride are mixed. The step of providing a mixture and heat treating said mixture at a pressure in the range of 10 atmospheres or less may be included. The heat treatment is preferably performed at a pressure in the range of 1 atmosphere to 10 atmospheres.

According to the production method of the present invention, a hydride or nitride containing at least one element A selected from the group consisting of alkaline earth metal elements, boron nitride, and optionally Tb, Sm, Pr, A mixture is prepared using as a raw material a compound containing at least one element M1 selected from the group consisting of Ce, Mn and Yb. A mixture containing raw materials may not contain a compound containing the element M1. In the production method according to the present invention, the mixture containing the raw materials is heat-treated at a pressure in the range of 10 atmospheres or less (1.0 MPa or less) to excite light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less. Thus, a boron nitride phosphor having at least one emission peak wavelength in the range of 480 nm or more and less than 650 nm can be produced. According to the manufacturing method, it is possible to obtain a boron nitride phosphor that emits light when excited by light having an emission peak wavelength in the range of 250 nm to 460 nm without heat treatment under a high pressure exceeding 10 atm. The atmospheric pressure during heat treatment varies depending on the temperature during heat treatment, and the atmospheric pressure during heat treatment is preferably in the range of 8 atmospheres or less (0.8 MPa or less), more preferably 5 atmospheres or less (0.5 MPa or less). be. The lower limit of the atmospheric pressure during the heat treatment is not particularly limited, but is preferably 0.1 atmospheric pressure or higher (0.01 MPa or higher) or 1 atmospheric pressure or higher.

Examples of hydrides containing at least one element A selected from the group consisting of alkaline earth metal elements include MgH ₂ , CaH ₂ , SrH ₂ and BaH ₂ . Nitrides containing at least one element selected from _the group consisting of _alkaline earth _metal elements include _Mg3N2 , _Ca3N2 , _Sr3N2 , _{SrN and Ba3N2 .} In the manufacturing method according to the third embodiment of the present invention, it is preferable to use a hydride containing the element A as a raw material because it is easily available and has relatively high reactivity.

Examples of compounds containing at least one element M1 selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb include oxides, chlorides, fluorides and nitrides containing the element M1. . From the viewpoint of easy availability and easy handling, it is preferable to use an oxide or nitride containing the element M1 as necessary. Specific examples _of compounds containing the element M1 include _Tb4O7 , _TbF3 , _Sm2O3 , _SmN , _{SmF3 , Pr6O11} , PrN, _PrF3 , _Ce2O3 , _{CeO2 , CeF3} , MnO, _Mn2O3 , _MnO2 , _{Yb2O3 , YbN} , _YbF3 .

The heat treatment atmosphere is preferably an inert atmosphere or a reducing atmosphere in order to obtain a boron nitride phosphor with few crystal defects. Examples of the inert atmosphere include at least one rare gas atmosphere selected from the group consisting of helium, neon and argon, and a nitrogen gas atmosphere. An inert atmosphere refers to an atmosphere having helium, neon, argon or nitrogen as the main component in the atmosphere. An inert atmosphere may inevitably contain oxygen as an impurity. In this specification, an inert atmosphere is defined as an atmosphere having an oxygen concentration of 15% by volume or less. The concentration of oxygen in the inert atmosphere is preferably 10% by volume or less, more preferably 5% by volume or less, and even more preferably 1% by volume or less. Examples of the reducing atmosphere include a rare gas atmosphere containing hydrogen and a nitrogen gas atmosphere containing hydrogen. The reducing atmosphere refers to an atmosphere containing hydrogen gas and rare gas, or hydrogen gas and nitrogen gas as main components.

The heat treatment temperature is preferably in the range of 1200° C. or higher and 1600° C. or lower. The heat treatment temperature is more preferably in the range of 1250° C. or higher and 1550° C. or lower, and more preferably in the range of 1300° C. or higher and 1500° C. or lower. If the heat treatment temperature is in the range of 1200° C. or higher and 1600° C. or lower, it is excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, and at least one emission peak wavelength is in the range of 480 nm or more and less than 650 nm. It is possible to obtain a boron nitride phosphor containing the composition represented by the above formula (I).

At least one emission in the range of 480 nm or more and less than 650 nm when excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, including a composition represented by the following formula (I) by the production method according to the present invention A boron nitride phosphor having a peak wavelength is obtained.
A ₃ B ₂ N ₄ : M1 _x (I)
(In formula (I), A is at least one element selected from the group consisting of alkaline earth metal elements, and M1 is selected from the group consisting of Tb, Sm, Pr, Ce, Mn and Yb. At least one element, and x is a number that satisfies 0≤x≤0.10.)

At least one emission in the range of 480 nm or more and less than 650 nm when excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, including the composition represented by the following formula (II) by the production method according to the present invention A boron nitride phosphor having a peak wavelength is obtained.
_{A3B2N4 ( II} )
(In formula (II), A is at least one element selected from the group consisting of alkaline earth metal elements.)

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples. The invention is not limited to these examples.

Example 1
12.6 g of calcium hydride (CaH ₂ ) and 5.0 g of boron nitride (BN) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to obtain a mixture. This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated product was pulverized to obtain a boron nitride compound represented by Ca ₃ B ₂ N ₄ .

Example 2
12.6 g of calcium hydride (CaH ₂ ), 5.0 g of boron nitride (BN), and 0.2 g of terbium oxide (Tb ₄ O ₇ ) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to form a mixture. got This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated product was pulverized to obtain a boron nitride compound represented by Ca ₃ B ₂ N ₄ :Tb.

Example 3
12.6 g of calcium hydride (CaH ₂ ), 5.0 g of boron nitride (BN), and 0.2 g of samarium oxide (Sm ₂ O ₃ ) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to form a mixture. got This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated material was pulverized to obtain a boron nitride compound represented by Ca ₃ B ₂ N ₄ :Sm.

Example 4
12.6 g of calcium hydride (CaH ₂ ), 5.0 g of boron nitride (BN), and 0.2 g of praseodymium oxide (Pr ₆ O ₁₁ ) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to form a mixture. got This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated product was pulverized to obtain a boron nitride compound represented by Ca ₃ B ₂ N ₄ :Pr.

Example 5
20.9 g of barium hydride (BaH ₂ ) and 2.5 g of boron nitride (BN) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to obtain a mixture. This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated product was pulverized to obtain a boron nitride compound represented by Ba ₃ B ₂ N ₄ .

Example 6
13.4 g of strontium hydride (SrH ₂ ) and 2.5 g of boron nitride (BN) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to obtain a mixture. This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated product was pulverized to obtain a boron nitride compound represented by Sr ₃ B ₂ N ₄ .

Comparative example 1
12.6 g of calcium hydride (CaH ₂ ), 5.0 g of boron nitride (BN), and 0.2 g of europium oxide (Eu ₂ O ₃ ) were weighed and mixed for 20 minutes using an agate mortar and an agate pestle to form a mixture. got This mixture was heat-treated at 1350° C. in a nitrogen gas atmosphere of 1 atm (0.10 MPa) for 10 hours. The obtained heat-treated product was pulverized to obtain a boron nitride compound.

Comparative example 2
A boron nitride compound was obtained in the same manner as in Comparative Example 1, except that the heat treatment temperature was set to 1250°C.

Comparative example 3
A boron nitride compound was obtained in the same manner as in Comparative Example 1, except that the heat treatment temperature was set to 1450°C.

Comparative example 4
_{Comparative _} A boron nitride compound was obtained in the same manner as in Example 1.

Comparative example 5
_{Comparative _} A boron nitride compound was obtained in the same manner as in Example 1.

Comparative example 6
A boron nitride compound was obtained in the same manner as in Comparative Example 1, except that 0.2 g of europium nitride (EuN) was used instead of 0.2 g of europium oxide (Eu ₂ O ₃ ).

X-Ray Diffraction Spectrum An X-ray diffraction spectrum (XRD) was measured for the obtained boron nitride compound. The measurement was performed using a sample horizontal multi-purpose X-ray diffractometer (product name: Ultima IV, manufactured by Rigaku Corporation) using CuKα rays. The presence or absence of formation of each alkaline earth metal boron nitride compound was confirmed from the obtained XRD pattern. In Examples 1 to 4, crystals having a composition represented by Ca ₃ B ₂ N ₄ were formed. In Example 5 and Comparative Example 4, crystals having a composition represented by Ba ₃ B ₂ N ₄ were formed. In Example 6 and Comparative Example 5, crystals having a composition represented by Sr ₃ B ₂ N ₄ were formed. In Comparative Examples 1 to 3 and 6, crystals having a composition represented by Ca ₃ B ₂ N ₄ were formed. Table 1 shows the composition of each example.

Light Emitting Property The light emitting property of the obtained boron nitride compound was measured. Emission characteristics were measured with a spectrofluorophotometer (product name: quantum efficiency measurement system QE-2000, manufactured by Otsuka Electronics Co., Ltd.) with an excitation light emission peak wavelength of 365 nm. Its emission spectrum is shown in FIGS. 1 to 6. FIG. In addition, although the emission intensity at the emission peak wavelength of Example 1 was the largest among the examples, in order to facilitate comparison of the emission spectrum shapes of the boron nitride compounds of each example, in each emission spectrum, the maximum emission intensity The intensity was taken as 100%. In addition, Table 1 shows the emission peak wavelength and half-value width in each emission spectrum. The half width refers to the full width at half maximum (FWHM) of the maximum emission peak in the emission spectrum, and the wavelength width of the emission peak showing a value of 50% of the maximum value of the maximum emission peak in each emission spectrum. say. Table 1 shows the results.

Excitation spectrum measurement For the boron nitride compounds of Examples 4 to 6, using a spectrofluorometer (product name: F-4500, manufactured by Hitachi High-Technologies Corporation), Example 4 was 515 nm, Example 5 was 595 nm, In Example 6, the excitation spectrum was measured at 610 nm in the range of 220 nm or more and 520 nm or less at 25° C.±5° C. (room temperature). FIG. 7 shows excitation spectra showing the relative intensity (%) at each wavelength, with the maximum intensity of each excitation spectrum of Examples 4 to 6 being 100%.

Reliability evaluation based on temperature characteristics: relative luminous energy (%)
Regarding the boron nitride compound containing the composition represented by Ca ₃ B ₂ N ₄ of Example 1 and the orthosilicate phosphor containing the composition represented by (Sr, Ba) ₂ SiO ₄ :Eu ²⁺ as a reference example, 25 Each emission spectrum excited by light from an excitation light source with an emission peak wavelength of 365 nm in a temperature range from ° C. (room temperature) to 150 ° C. was measured with a spectrofluorometer (product name: quantum efficiency measurement system QE-2000, Otsuka (manufactured by Denshi Co., Ltd.). With the energy value of the emission spectrum measured at 25 ° C. of Examples and Reference Examples as 100%, the relative emission spectrum energy value (relative emission energy (%)) of the phosphors of Examples and Reference Examples at each temperature asked. The energy value is a relative integrated value within the wavelength range of 480 nm or more and 650 nm or less in the emission spectrum obtained at each temperature. FIG. 8 is a graph showing the relative emission energy (%) of the boron nitride compound of Example 1 and the orthosilicate phosphor of Reference Example at each temperature in the temperature range from 25° C. (room temperature) to 150° C. FIG.

As shown in Table 1 and FIG. 1, the boron nitride compound represented by Ca ₃ B ₂ N ₄ of Example 1 is a boron nitride phosphor having an emission peak wavelength of 515 nm, which is attributed to host emission. rice field.
As shown in Table 1 and FIG. 2, the boron nitride compound represented by Ca ₃ B ₂ N ₄ :Tb of Example 2 has a first emission peak at 489 nm due to host emission. , and Tb, the boron nitride phosphor having a second emission peak having an emission peak wavelength at 545 nm.
As shown in Table 1 and FIG. 3, the boron nitride compound represented by Ca ₃ B ₂ N ₄ :Sm of Example 3 has a first emission peak at 515 nm due to host emission. , and Sm, namely, a second emission peak having an emission peak wavelength of 607 nm and a third emission peak having an emission peak wavelength of 651 nm. The emission intensity of the second emission peak and the third emission peak of the boron nitride phosphor of Example 3 is lower than that of the first emission peak.
As shown in Table 1 and FIG. 4, the boron nitride compound represented by Ca ₃ B ₂ N ₄ :Pr of Example 4 has a first emission peak at 515 nm due to host emission. , Pr, that is, a boron nitride phosphor having two emission peaks, namely, a second emission peak having an emission peak wavelength at 610 nm and a third emission peak having an emission peak wavelength at 637 nm. The emission intensity of the second emission peak and the third emission peak of the boron nitride phosphor of Example 4 is lower than that of the first emission peak.
As shown in Table 1 and FIG. 5, the boron nitride compound represented by Ba ₃ B ₂ N ₄ in Example 5 was a boron nitride phosphor having an emission peak wavelength of 600 nm due to the host emission. rice field.
As shown in Table 1 and FIG. 6, the boron nitride compound represented by Sr ₃ B ₂ N ₄ of Example 6 is a boron nitride phosphor having an emission peak wavelength of 610 nm, which is attributed to host emission. rice field.

None of the boron nitride compounds containing Eu according to Comparative Examples 1 to 6 emitted light. Europium is considered to be a killer element that inhibits the emission of boron nitride compounds represented by Ca ₃ B ₂ N ₄ , Ba ₃ B ₂ N ₄ or Sr ₃ B ₂ N ₄ .

As shown in FIG. 7, the boron nitride phosphor according to Example 4 has the highest relative intensity in the excitation spectrum in the wavelength range of 320 nm or more and 370 nm or less, and the boron nitride phosphors of Examples 5 and 6 have the highest relative intensity at 370 nm. The relative intensities were highest in the excitation spectrum within the wavelength range above 420 nm. FIG. 7 shows that boron nitride phosphors with different excitation spectra can be obtained by selecting the elements contained in the composition of the boron nitride phosphor. That is, by selecting the emission peak wavelength of the excitation light source and the elements contained in the composition of the boron nitride phosphor, the boron nitride phosphor according to the present embodiment can efficiently emit light having various emission spectra. can be done.

As shown in FIG. 8, the boron nitride phosphor of Example 1 had a higher relative emission energy than the orthosilicate phosphor in the temperature range of 25° C. (room temperature) to 150° C., and had good temperature characteristics.

INDUSTRIAL APPLICABILITY The boron nitride phosphor according to the present invention can be used in light-emitting devices for illumination or projectors using LEDs or LDs as excitation light sources.

Claims (9)

Boron nitride having at least one emission peak wavelength in the range of 480 nm or more and less than 550 nm when excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, and containing a composition represented by the following formula (I) Phosphor.
Ca3B2N4 _{: M1x (} I ₎
(In formula (I), M1 is at least one element selected from the group consisting of Tb, Sm and Pr , and x is a number that satisfies 0≤x≤0.10.) Boron nitride having at least one emission peak wavelength in the range of 480 nm or more and less than 650 nm when excited by light having an emission peak wavelength in the range of 250 nm or more and 460 nm or less, and containing a composition represented by the following formula (II) Phosphor.
_{A3B2N4 ( II} )
(In formula (II), A is at least one element selected from the group consisting of alkaline earth metal elements.) 2. The boron nitride phosphor according to claim 1 , wherein in formula (I), x is a number that satisfies 0≤x≤0.03. A light-emitting device comprising the boron nitride phosphor according to claim 1 and an excitation light source. 5. The light emitting device according to claim 4 , wherein said excitation light source is a light emitting diode or a semiconductor laser. preparing a mixture of a hydride or nitride containing Ca , boron nitride, and optionally a compound containing at least one element M1 selected from the group consisting of Tb, Sm and Pr ; at a pressure of 10 atmospheres or less, wherein the obtained boron nitride phosphor has a composition represented by the following formula (I).
Ca3B2N4 _{: M1x (} I ₎
(In formula (I), M1 is at least one element selected from the group consisting of Tb, Sm and Pr , and x is a number that satisfies 0≤x≤0.10.) Prepare a mixture of a hydride or nitride containing at least one element A selected from the group consisting of alkaline earth metal elements and a compound containing boron nitride, and pressurize the mixture at a pressure of 10 atmospheres or less wherein the obtained boron nitride phosphor has a composition represented by the following formula (II).
_{A3B2N4 ( II} )
(In formula (II), A is at least one element selected from the group consisting of alkaline earth metal elements.) 8. The method for producing a boron nitride phosphor according to claim 6 , wherein the atmosphere for said heat treatment is an inert atmosphere or a reducing atmosphere. The method for producing a boron nitride phosphor according to any one of claims 6 to 8 , wherein the heat treatment temperature is in the range of 1200°C or higher and 1600°C or lower.

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