PHOSPHOR

Abstract

A phosphor having an elemental composition represented by the following composition formula: Sr.sub.yMg.sub.(1x)M.sub.xAl.sub.zO.sub.(1+y+1.5z) (1), in the formula (1), M represents at least one metal element selected from the group consisting of manganese, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, and ytterbium, x represents a value of 0.01x0.8, y represents a value of 1y2, and z represents a value of 10z22, wherein a particle diameter D10 at which a cumulative frequency is 10% and a particle diameter D90 at which a cumulative frequency is 90% in a volume-based cumulative particle diameter distribution curve obtained by a laser diffraction scattering method satisfy the following conditions (I) and (II): (I) D90-D10 is less than 67.4 m; and (II) D10 is a value of greater than 1.3 m and 100 m or less.

Claims

1. A phosphor having an elemental composition represented by the following composition formula:
Sr.sub.yMg.sub.(1x)M.sub.xAl.sub.zO.sub.(1+y+1.5z)(1) in the formula (1), M represents at least one metal element selected from the group consisting of manganese, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, thulium, and ytterbium, x represents a value of 0.01x0.8, y represents a value of 1y2, and z represents a value of 10z22, wherein a particle diameter D10 at which a cumulative frequency is 10% and a particle diameter D90 at which a cumulative frequency is 90% in a volume-based cumulative particle diameter distribution curve obtained by a laser diffraction scattering method satisfy the following conditions (I) and (II): (I) D90-D10 is less than 67.4 m; and (II) D10 is a value of greater than 1.3 m and 100 m or less.

2. The phosphor according to claim 1, wherein y is 2, and z is 22.

3. The phosphor according to claim 1, wherein M is manganese.

4. A film comprising the phosphor according to claim 1.

5. A light-emitting element comprising the phosphor according to claim 1.

6. A light-emitting device comprising the light-emitting element according to claim 5.

7. A display comprising the light-emitting element according to claim 5.

8. A phosphor wheel comprising the phosphor according to claim 1.

9. A projector comprising the phosphor wheel according to claim 8.

10. A method for producing the phosphor according to claim 1, comprising firing a raw material mixture containing a Sr compound as a raw material of a Sr element, a Mg compound as a raw material of a Mg element, an M compound as a raw material of an M element, and an Al compound as a raw material of an Al element.

Description

EXAMPLES

[0150] Hereinafter, the present invention will be described in more detail with reference to Examples. The present invention is not limited to these Examples.

Example 1

[0151] Aluminum oxide powder (grade AA-18, specific surface area: 0.1 m.sup.2/g, D50: 20.3 m, manufactured by Sumitomo Chemical Co., Ltd.), magnesium carbonate powder, manganese carbonate powder, and strontium carbonate powder were used as raw materials of the phosphor, and the raw materials were weighed so that the composition of raw materials to be fed was Mn:Mg:Al:Sr=0.3:0.7:22:2 in a molar ratio, and dry-mixed for 3 minutes. Next, the mixed raw materials were filled in an alumina container. Subsequently, the alumina container was set in an electric furnace, and a mixed gas of hydrogen:nitrogen=10:90 was introduced into the furnace. The temperature was raised to 1,550 C., and the mixed raw materials were fired for 6 hours, and then allowed to cool. The fired product was recovered from the container to produce a phosphor of Example 1. The produced phosphor had a specific surface area of 0.163 m.sup.2/g.

Example 2

[0152] A phosphor of Example 2 was produced in the same manner as in Example 1 except that the composition of the mixed gas was changed to hydrogen:nitrogen=5:95 and the firing temperature was changed to 1,400 C. The produced phosphor had a specific surface area of 0.0891 m.sup.2/g.

Example 3

[0153] A phosphor of Example 3 was produced in the same manner as in Example 1 except that barium fluoride as a flux was mixed so as to be 5 wt % with respect to the total amount of raw materials of the phosphor. The produced phosphor had a specific surface area of 0.256 m.sup.2/g.

Example 4

[0154] Aluminum oxide powder (grade AA-3, specific surface area: 0.5 m.sup.2/g, D50: 3.5 m, manufactured by Sumitomo Chemical Co., Ltd.), magnesium carbonate powder, manganese carbonate powder, and strontium carbonate powder were used as raw materials of the phosphor, and the raw materials were weighed so that the composition of raw materials to be fed was Mn:Mg:Al:Sr=0.3:0.7:22:2 in a molar ratio, then barium fluoride as a flux was mixed therein so as to be 5 wt % with respect to the total amount, followed by dry-mixing for 3 minutes. Next, the mixed raw materials were filled in an alumina container. Subsequently, the alumina container was set in an electric furnace, and a mixed gas of hydrogen:nitrogen=5:95 was introduced into the furnace. The temperature was raised to 1,400 C., and the mixed raw materials were fired for 6 hours, and then allowed to cool. The fired product was recovered from the container to produce a phosphor of Example 4.

[0155] <Comparative Example>

[0156] A phosphor of Comparative Example was produced in the same manner as in Example 1 except that aluminum oxide powder (grade AA-05, specific surface area: 3.2 m.sup.2/g, D50: 0.58 m, manufactured by Sumitomo Chemical Co., Ltd.) was used instead of the aluminum oxide powder (grade AA-18). The produced phosphor had a specific surface area of 2.10 m.sup.2/g.

[0157] <Various Measurements and Evaluations>

[0158] The following items were measured for the phosphors produced in Examples and Comparative Examples. [0159] (a) Crystal Structure and Full Width at Half Maximum for XRD Peak

[0160] Powder X-ray diffraction using CuK.sub. rays was performed with an X-ray diffractometer (X'Pert Pro (trade name) manufactured by PANalytical). The obtained X-ray diffraction pattern showed a crystal structure of ICSD #82105 having a hexagonal structure and having a peak of the 100 plane at a position of 2=15 to 25 and a peak of the 001 plane at a position of 2=5 to 15 in all the samples.

[0161] The full width at half maximum of the XRD peak at 2=31.70.5 was calculated using integrated powder X-ray diffraction software PDXL (manufactured by Rigaku Corporation). [0162] (b) Specific Surface Area

[0163] The specific surface area by the BET method was measured with a full automatic BET specific surface area analyzer (MacsorbHM-1208 (trade name) manufactured by Mountech Co., Ltd.). [0164] (c) Particle Diameter Distribution

[0165] The particle diameter distribution was measured with a laser diffraction particle diameter analyzer (Mastersizer 2000: manufactured by Malvern Panalytical, water solvent). [0166] (d) Emission Intensity and Full Width at Half Maximum of Emission Peak

[0167] The emission spectrum was measured with an absolute PL quantum yield spectrometer (trade name 09920-02, manufactured by Hamamatsu Photonics K.K., excitation light: 450 nm, room temperature, in the air, 150 mg), and the emission intensity and the full width at half maximum of the emission peak were measured. When emission at 470 to 800 nm was measured, it was confirmed that all the phosphors were green light-emitting phosphors showing a maximum emission peak in a range of 510 nm to 550 nm. A method for evaluating the emission intensity is described below.

[0168] The area of the emission peak was determined from the measured spectrum, and converted into a percentage with the emission peak area of Example 4 as 100% to calculate the relative emission intensity. Evaluation criteria of the relative emission intensity were as follows. [0169] A: 145% or more (good), [0170] B: 100% or more (acceptable), [0171] C: less than 100% (not acceptable).

[0172] The characteristic values and evaluation results of the phosphors of Examples and Comparative Examples are summarized in Table 1.

TABLE-US-00001 TABLE 1 Compar- Composition*: Exam- Exam- Exam- Exam- ative Sr.sub.2Mg.sub.0.7Mn.sub.0.3Al.sub.22O.sub.36 ple 1 ple 2 ple 3 ple 4 Example D50 (m) 21.3 21.6 23.9 8.93 4.12 Full width at 0.124 0.130 0.183 0.184 0.207 half maximum of XRD peak at 2 = 37.0 0.5 () D90 D10 (m) 15.4 15.6 19.6 44.5 67.4 D10 (m) 14.9 15.1 16.0 3.5 1.3 Full width at 26.4 26.9 27.1 27.3 27.7 half maximum of emission peak (nm) Relative emission 145% 154% 151% 100% 72% intensity Evaluation A A A B C *Composition of raw materials to be fed.

[0173] Table 1 shows that Sr.sub.2Mg.sub.0.7Mn.sub.0.3Al.sub.22O.sub.36 phosphors, in which D90-D10 is 15.4 to 44.5 m and D10 is 3.5 to 16.0 m, in particular, those in which D90-D10 is 15.4 to 19.6 m and D10 is 14.9 to 16.0 m, have enhanced emission intensity.

[0174] Table 1 also shows that Sr.sub.2Mg.sub.0.7Mn.sub.0.3Al.sub.22O.sub.36 phosphors, in which the full width at half maximum of the XRD peak at 2=37.00.5 is 0.124 to 0.184, have a narrow full width at half maximum of the emission peak and thus have a narrowed emission peak.

Reference Example 1

[0175] The phosphors described in Examples 1 to 4 are combined with a resin, the resulting composite material is sealed in a glass tube or the like, and then the glass tube is disposed between a blue light-emitting diode as a light source and a light guiding plate, thereby producing a backlight capable of converting blue light of the blue light-emitting diode into green light or red light.

Reference Example 2

[0176] A resin composition can be obtained by combining the phosphors described in Examples 1 to 4 with a resin to form a sheet. A film prepared by sandwiching and sealing the sheet of the resin composition with two barrier films is disposed on a light guiding plate, thereby producing a backlight capable of converting, blue light emitted from a blue light-emitting diode placed on an end surface (side surface) of the light guiding plate to the sheet through the light guiding plate, into green light or red light.

Reference Example 3

[0177] The phosphors described in Examples 1 to 4 are disposed in the vicinity of a light-emitting part of a blue light-emitting diode, thereby producing a backlight capable of converting emitted blue light into green light or red light.

Reference Example 4

[0178] A wavelength conversion material can be obtained by mixing the phosphors described in Examples 1 to 4 with a resist and then removing the solvent from the mixture. The obtained wavelength conversion material is disposed between a blue light-emitting diode as a light source and a light guiding plate or at a rear stage of an organic light-emitting diode (OLED) as a light source, thereby producing a backlight capable of converting blue light of the light source into green light or red light.

Reference Example 5

[0179] The phosphors described in Examples 1 to 4 are mixed with conductive particles such as ZnS particles to form a film, an n-type transport layer is laminated on one side of the film, and a p-type transport layer is laminated on the other side of the film, to thereby obtain an LED. When a current flows through the LED, holes of the p-type semiconductor and electrons of the n-type semiconductor cancel the charge in the perovskite compound of the junction surface, so that light can be emitted.

Reference Example 6>

[0180] A titanium oxide dense layer is laminated on the surface of a fluorine-doped tin oxide (FTO) substrate, a porous aluminum oxide layer is laminated thereon, each of the phosphors described in Examples 1 to 4 is laminated thereon, after removing the solvent, a hole transport layer made of 2,2,7,7-tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene (Spiro-OMeTAD) or the like is laminated thereon, and a silver (Ag) layer is laminated thereon to produce a solar cell.

Reference Example 7

[0181] A composition of the present embodiment can be obtained by combining the phosphors described in Examples 1 to 4 with a resin and molding the resulting composite material. This composition is disposed at a rear stage of a blue light-emitting diode, thereby producing laser diode illumination that converts, blue light emitted from the blue light-emitting diode to the composition, into green light or red light and emits white light.

Reference Example 8

[0182] The composition of the present embodiment can be obtained by combining the phosphors described in Examples 1 to 4 with a resin and molding the resulting composite material. The obtained composition is used for a photoelectric conversion layer, thereby producing a photoelectric conversion element (photodetection element) material used for and contained in a detection part that detects light. The photoelectric conversion element material is used for an image detection part (image sensor) for solid-state imaging devices such as X-ray imaging devices and CMOS image sensors, a detection part that detects a predetermined feature of a part of a living body, such as a fingerprint detection part, a face detection part, a vein detection part, and an iris detection part, and an optical biosensor such as a pulse oximeter.

Reference Example 9

[0183] The composition of the present embodiment can be obtained by combining the phosphors described in Examples 1 to 4 with a resin and molding the resulting composite material. The obtained composition can be used as a film for improving the light conversion efficiency of a solar cell. The form of the conversion efficiency improvement sheet is not particularly limited, and the sheet is used in the form of applying the composition to a substrate. The substrate is not particularly limited as long as it is a substrate having high transparency. For example, a PET film, or a moth-eye film is desirable. The solar cell produced using the solar cell conversion efficiency improvement sheet is not particularly limited, and the conversion efficiency improvement sheet has a conversion function from a wavelength range where the sensitivity of the solar cell is low to a wavelength range where the sensitivity is high.

Reference Example 10

[0184] The composition of the present embodiment can be obtained by combining the phosphors described in Examples 1 to 4 with a resin and molding the resulting composite material. The obtained composition can be used as a light source for single photon generation such as a quantum computer, quantum teleportation, and quantum cryptographic communication.