JP4790794B2 - Red phosphor, red light emitting device or device, and white light emitting device or device - Google Patents

Description

  The present invention is a red phosphor, specifically a white LED light source, a fluorescent display tube (VFD), a field emission display (FED), an electroluminescence (EL), etc., and a red phosphor used therefor The present invention relates to a red / white light emitting element or device.

  As a conventional red phosphor, a ZnCdS: Ag, Cl phosphor has been mainly used because it is chemically stable. However, the use of Cd is limited due to environmental problems. Development of a new red phosphor that does not contain Cd has been required, and a new red phosphor has been developed.

  For example, Patent Document 1 and Patent Document 2 contain calcium sulfide as a base material, Eu as a luminescent center (activator), and Mn, Li, Cl, Ce, Gd, and the like as sensitizers (coactivators). A red phosphor is disclosed.

  Patent Document 3 discloses a general formula (Ca, Sr) S: Eu, A, F, () as a red phosphor capable of obtaining high luminance and good luminance and efficiency even in low-speed electron excitation. 1), (Ca, Sr) S: Eu, Rb, F (2), or (Ca, Sr) S: Eu, A, Rb, F (3) Red phosphor (wherein A in the formulas (1) to (3) is at least one selected from Al, Ga and In, 0.01 to 5 mol%, and Rb is 0.01 to 2 mol) % Content) is disclosed.

JP 2002-80845 A JP 2003-41250 A JP 2005-146190 A

  Since the red phosphor has lower visibility than the green and orange phosphors and inherently low luminance, a red phosphor that can sufficiently increase the luminance is required.

  In general, red phosphors are used in televisions and other applications where deep red is required, while LEDs and other lighting applications require orange red. It is preferable that the material can adjust the color. In that respect, the (Ca, Sr) S: Eu red phosphor disclosed in Patent Document 3 is excellent in that the emission wavelength can be adjusted according to the application by adjusting the blending ratio of Ca and Sr. Yes.

  Furthermore, since there are those that do not like the generation of halogen-based gas depending on the application, it is preferable that the red phosphor does not use halogen.

  Accordingly, an object of the present invention is to advance research on a (Ca, Sr) S: Eu-based red phosphor, and to increase brightness even more without using halogen as a sensitizer or flux. It is to provide a (Ca, Sr) S: Eu-based phosphor.

The present invention is a red phosphor represented by the general formula: (Ca _1-x Sr _x ) S: Eu, In (wherein x is 0 to 1), and the total number of moles of Ca and Sr A red phosphor containing 0.05 to 4.0 mol% of In (hereinafter, “mol%” means mol% relative to the total number of moles of Ca and Sr unless otherwise specified), That is, a red phosphor having (Ca _1-x Sr _x ) S as a base and Eu as an emission center (activator), containing 0.05 to 4.0 mol% of In, and halogen The present invention proposes a red phosphor substantially free of elements, particularly F (fluorine).

  Note that “substantially not containing a halogen element” means that halogen is not actively added as a sensitizer or flux, and does not exclude the case where a halogen element is included as an inevitable impurity.

  Thus, in a red phosphor having (Ca, Sr) S as a base and Eu as an emission center, if In is added, (Ca, Sr) can be obtained without adding a halogen element such as F or Cl. Light emission associated with defects in the S matrix can be suppressed, and at the same time, the luminance can be improved by increasing the red light emission intensity. In particular, by mixing 0.05 mol% or more of In, the emission peak associated with the defect of the matrix can be eliminated, and a very strong red emission spectrum with a single peak can be obtained. Red purity, red emission intensity, and luminance Can be significantly increased.

  Furthermore, by adjusting the amount of In according to the type of excitation source, the emission intensity can be further increased and the luminance can be further improved.

  For example, in the case of photoexcitation, by setting the In content to 0.05 to 2.5 mol%, the PL intensity can be increased compared to the case where In is not added, and the In content is 0.1%. By setting it to ˜1.5 mol%, the PL strength can be further increased as compared with the case where In is not added. Such an effect is an excellent effect compared with the case where Al or Ga is blended instead of In.

  Accordingly, the present invention generates a red phosphor for photoexcitation containing 0.05 to 2.5 mol% of In in the red phosphor of the present invention as described above, and such red phosphor and excitation light. A red light emitting element or device including a light source, and a white light emitting element or device including such a red phosphor, a blue to green phosphor, and a light source that generates excitation light are proposed.

  In addition, in the case of electron beam excitation, by setting the In content to 0.05 to 4.0 mol%, the CL intensity can be increased as compared with the case where In is not added, and the In content is reduced. By setting it as 0.1-2.0 mol%, CL intensity | strength can further be raised compared with the case where In is not added. Such an effect is a particularly excellent effect even when Al or Ga is blended in place of In.

  Therefore, the present invention provides a red phosphor for electron beam excitation containing 0.05 to 4.0 mol% of In in the red phosphor of the present invention as described above, and such a red phosphor and an electron beam. A red light emitting element or device provided with an electron source for generating light, and a white light emitting element or device provided with such a red phosphor, blue or green phosphor and an electron source for generating an electron beam are proposed.

  The red phosphor of the present invention may be in the form of a powder or a molded body.

  In the present invention, the “light emitting element” in the “red light emitting element or apparatus” is intended to be a light emitting device that emits a relatively small light and includes at least a phosphor and a light emitting source or an electron source as an excitation source thereof. The term “light emitting device” is intended to mean a light emitting device that emits a relatively large amount of light and includes at least a phosphor and a light emitting source or an electron source as an excitation source thereof.

  Further, in the present invention, when expressed as “X to Y” (X and Y are arbitrary numbers), unless otherwise specified, “X or more and Y or less” and “preferably larger than X and smaller than Y”. The meaning is also included.

  As described above, the red phosphor of the present invention adjusts the mixing ratio of Ca and Sr in the matrix so that the emission wavelength can be adjusted according to the use, and also emits red light by light excitation or electron beam excitation, Even without adding a halogen element such as F or Cl, the red purity and brightness can be sufficiently increased. Therefore, it is particularly suitable as a red phosphor and a red light emitting element or device used for a white LED light source, a fluorescent display tube (VFD), a field emission display (FED), an electroluminescence (EL), and the like.

(A) is the figure which showed CL spectrum of In addition samples 1-8, (B) is the figure which showed CL spectrum of In addition samples 19-21. (A) is the figure which showed the PL spectrum of In addition samples 1-8, (B) is the figure which showed the PL spectrum of In addition samples 19-21. It is the figure which showed CL spectrum of Ga addition samples 9-13. It is the figure which showed PL spectrum of Ga addition samples 9-13. It is the figure which showed CL spectrum of Al addition samples 14-18. It is the figure which showed PL spectrum of Al addition samples 14-18. It is the figure which showed the relationship between the addition amount of In, Ga, and Al, and PL relative intensity about the samples 1-21. It is the figure which showed the relationship between the addition amount of In, Ga, and Al, and CL relative intensity about the samples 1-21. It is the figure which showed PL spectrum of the red fluorescent substance obtained by Test 1. FIG. It is the figure which showed CL spectrum of In addition samples 22-28. It is the figure which showed PL spectrum of In addition samples 22-28. It is the figure which showed the relationship between the addition amount of In and PL relative intensity about samples 22-31. It is the figure which showed the relationship between the addition amount of In and CL relative intensity about samples 22-31.

BEST MODE FOR CARRYING OUT THE INVENTION

  Hereinafter, a red phosphor according to an example of an embodiment of the present invention (hereinafter referred to as “the present red phosphor”) will be described in detail. However, the scope of the present invention is not limited to the embodiments described below.

The red phosphor has (Ca _1-x Sr _x ) S as a base, Eu as a luminescent center (activator), 0.05 to 4.0 mol% of In, and a halogen element, particularly It is a red phosphor that does not substantially contain F (fluorine).

The matrix of the red phosphor can be represented by (Ca _1-x Sr _x ) S.

  At this time, the maximum emission wavelength (emission peak wavelength) can be adjusted by adjusting the content (x) of strontium. That is, since the maximum emission wavelength of CaS: Eu is 650 nm, and the maximum emission wavelength of SrS: Eu is 590 nm, by adjusting the content ratio of calcium and strontium, the maximum emission wavelength (590 nm to 650 nm) can be obtained. The emission wavelength can be arbitrarily controlled.

  The strontium content (x) may be adjusted in the range of 0 to 1 depending on the application. For example, from the viewpoint of visibility, 0.5 to 1 is preferable, and 0.8 to 1 is more preferable. Moreover, from the viewpoint of red purity, 0 to 0.5 is preferable, and 0 to 0.2 is particularly preferable.

The emission center of the red phosphor is preferably divalent Eu ²⁺ . In the case of trivalent (Eu ³⁺ ), Eu does not dissolve in the (CaSr) S phase, and the red luminance decreases.

  The content of Eu is preferably 0.1 to 5 mol%, particularly preferably 0.5 to 2 mol%.

  It is important that the red phosphor contains 0.05 to 4.0 mol% of In and substantially does not contain a halogen element, particularly F (fluorine).

  In a red phosphor having (Ca, Sr) S as a base and Eu as an emission center, if a predetermined amount of In is blended, a (Ca, Sr) S base can be obtained without adding a halogen element such as F or Cl. The emission (emission peak) associated with the defect can be suppressed. In particular, when 0.05 mol% or more of In is blended, the emission (emission peak) associated with the defect of the matrix can be eliminated, and a very strong red emission spectrum with a single peak can be obtained. In addition, the red emission intensity and luminance can be significantly increased.

  From such a viewpoint, the In content in the red phosphor is preferably 0.05 to 4.0 mol%, more preferably 0.1 to 2.0 mol%, It is particularly preferable that the amount is ˜1.5 mol%.

  As shown in FIG. 3 and FIG. 5, in a red phosphor having (Ca, Sr) S as a base and Eu as an emission center, Al or Ga is added without adding a halogen element such as F or Cl. For example, an emission peak appears near 400 nm (400 nm ± 30 nm) or near 550 nm (550 nm ± 30 nm) in addition to the red light emission peak around 650 nm (650 nm ± 30 nm) by electron beam excitation of 5 kV. The light emission peak near 400 nm is considered to be due to light emission due to defects in the host material, and the light emission peak near 550 nm is considered to be due to light emission of thiogallate generated by the reaction of Ga with S of the host material.

  On the other hand, when a red phosphor having (Ca, Sr) S as a base and Eu as an emission center is mixed with In, as shown in FIGS. 1A and 1B and FIG. 10, F and Cl Even without adding a halogen element such as the above, an emission peak in the vicinity of 400 nm (400 nm ± 30 nm) can be suppressed.

  In particular, as shown in FIGS. 1A and 1B, in a red phosphor having CaS as a base and Eu as an emission center, by adding 0.05 mol% or more of In, the vicinity of 400 nm (400 nm ± 30 nm) and 550 nm (550 nm ± 30 nm), and a single peak red emission spectrum showing only an emission peak around 650 nm (650 nm ± 30 nm) can be obtained. Can be significantly increased.

  Further, as shown in FIG. 10, in a red phosphor having SrS as a base and Eu as an emission center, by mixing 0.2 mol% or more of In, around 400 nm (400 nm ± 30 nm) and around 550 nm A unimodal red emission spectrum that shows almost no emission peak at (550 nm ± 30 nm) and only an emission peak around 650 nm (650 nm ± 30 nm) can be obtained, and at the same time, the intensity of this red emission peak is significantly increased. Can do.

  The reason why such an effect can be obtained only in the case of In as compared with Al and Ga is that Al and Ga are remarkably smaller in ionic radius than Ca and Sr and difficult to dissolve in the mother body. Reaction products with host elements are likely to occur. Thus, by adding a halogen (especially F) that is highly reactive with alkaline earth metals, it becomes easier to form a solid solution. Therefore, it is considered that such a special effect can be obtained because it is easily dissolved in the base material without adding halogen.

  By specifying the amount of In according to the type of excitation light source, the emission intensity can be further increased and the luminance can be improved.

  For example, in the case of photoexcitation, as shown in FIG. 7 and FIG. 12, by increasing the content of In to 0.05 to 2.5 mol%, the PL intensity is increased as compared with the case where In is not added. By adjusting the In content to 0.05 to 1.5 mol%, the PL strength can be further increased as compared with the case where In is not added, and the In content is further increased to 0.2 to 1. By adjusting the content to 0.0 mol%, particularly 0.2 to 0.5 mol%, the PL strength can be further increased as compared with the case where In is not added. Such an effect is an exceptional effect that cannot be seen when Al or Ga is blended in place of In.

  In such photoexcitation, the excitation wavelength in the case of visible light excitation includes a region of 400 to 550 nm, preferably 450 to 520 nm, particularly preferably 470 to 500 nm.

  Further, the excitation wavelength in the case of ultraviolet excitation includes a region of 250 to 350 nm, preferably 260 to 300 nm, particularly preferably 270 to 290 nm.

  In the case of electron beam excitation, as shown in FIG. 8 and FIG. 13, by setting the In content to 0.05 to 4.0 mol%, the CL intensity is increased as compared with the case where In is not added. By adjusting the In content to 0.1 to 2.0 mol%, the CL strength can be further increased as compared with the case where In is not added, and the In content is further increased to 0.2 to 0.2 mol%. By setting it as 1.5 mol%, CL intensity | strength can further be raised compared with the case where In is not added. Such an effect is an exceptional effect that cannot be seen when Al or Ga is blended in place of In.

  In the case of electron beam excitation, an acceleration voltage of 10 V to 30 kV can be used.

If the red phosphor contains a predetermined amount of In, the charge compensator can be a cation metal capable of taking a monovalent valence, such as Cu ⁺ , Ag ⁺ , Li ⁺ , Na ⁺ , K ⁺ , Rb ^+. Or a rare earth element (excluding Eu) such as Ce, Sc, Y, La, Gd, and Lu as a sensitizer.

  The red phosphor may contain impurities as long as the effects of the present invention are not hindered. For example, oxygen and its oxides mixed from the atmosphere, alkaline earth metals such as Mg and Ba slightly contained in the raw materials, rare earth elements such as La, Y, and Gd, halogens slightly contained in water and cleaning liquid (F , Cl, I, etc.) may be mixed into the red phosphor as inevitable impurities. The content of these inevitable impurities is usually less than 1000 ppm, but it is considered that the content of such a level does not hinder the effect of the red phosphor. Therefore, if it is less than 1000 ppm, preferably less than 500 ppm, particularly preferably less than 100 ppm, the impurities as described above may be contained.

  Whether or not it has the composition of the present red phosphor is determined by measuring the amount of each element using an X-ray fluorescence analyzer (XRF) or an ICP emission analyzer after completely dissolving it with hydrochloric acid or the like. can do.

  The red phosphor may be a powder or a molded body. In the case of a powder, the particle size can be distributed in the range of 1 μm to 100 μm, and pulverized or classified according to the application. The particle size can be adjusted.

  In addition, the central particle size of the red phosphor can be adjusted by adjusting the particle size of the base material, that is, the Ca material or the Sr material, and may be adjusted according to the application.

  In addition, when a large amount of In is blended, the particle size distribution is widened and the ratio of fine powder and coarse powder tends to be high. From this viewpoint, the blending amount of In is 4.0 mol% or less, particularly 3.0 mol% or less, In particular, it is preferably 2.0 mol% or less.

  The red phosphor has a red emission spectrum having an emission peak around 650 nm (650 nm ± 30 nm, preferably ± 20 nm, particularly preferably ± 15 nm) by visible light excitation at a wavelength of 400 nm to 550 nm or ultraviolet excitation at a wavelength of 250 nm to 350 nm. Can be obtained (see FIGS. 2A and 2B).

  The red phosphor does not show an emission peak at around 400 nm (400 nm ± 30 nm) and around 550 nm (550 nm ± 30 nm) by electron beam excitation of 10 V or more, usually 10 V to 30 kV, and near 650 nm (650 nm). A monomodal red emission spectrum having an emission peak at ± 30 nm, preferably ± 20 nm, particularly preferably ± 15 nm) can be obtained (see FIGS. 1A and 1B).

  In applications using electron beam excitation, a fluorescent display tube (VFD) using an electron beam accelerated by a voltage of 10 to 150 V as an excitation source, and a low voltage using an electron beam accelerated by a voltage of 1 kV to 3 kV as an excitation source. A voltage type field emission display (FED) or a high voltage type field emission display (FED) using an electron beam applied at a voltage of 3 kV to 20 kV as an excitation source is used. It is also applicable to.

(Production method)
Next, an example of a preferable method for producing the red phosphor will be described. However, it is not limited to the manufacturing method demonstrated below.

  The red phosphor is prepared by weighing Sr raw material and / or Ca raw material, Eu raw material, In raw material, and S raw material as required, mixing the raw materials, firing in a reducing atmosphere, and annealing as necessary. Can be obtained.

  Examples of the Sr raw material and the Ca raw material include, in addition to simple metals, respective oxides, sulfides, double oxides, carbonates, and the like. Sulfides are preferable.

Examples of the In material include sulfides, oxides, double oxides, and carbonates in addition to simple metals. Specifically, In, In ₂ S ₃ , In ₂ O _{3 and the} like can be given.

Examples of the Eu raw material include europium compounds (Eu salts) such as EuS, Eu ₂ O ₃ and Eu.

Examples of the S raw material include SrS, S (sulfur), H ₂ S gas, and the like.

  Mixing of the raw materials may be performed either dry or wet.

  In the case of dry mixing, the mixing method is not particularly limited. For example, zirconia balls are used as a medium and mixed with a paint shaker or a ball mill (for example, about 90 minutes), and dried as necessary to obtain a raw material mixture. You can get it.

  In the case of wet mixing, the raw material is made into a suspension state using a non-aqueous solvent, and after mixing with a paint shaker or a ball mill using zirconia balls as a medium in the same manner as above, the medium is separated with a sieve or the like, and the pressure is reduced. The dry raw material mixture may be obtained by removing the solvent from the suspension by an appropriate drying method such as drying or vacuum drying.

  Before firing, the raw material mixture obtained as described above may be pulverized, classified, and dried as necessary. However, crushing, classification, and drying are not necessarily performed.

Moreover, you may shape | mold the obtained powder as needed. For example, it can be molded under the conditions of φ20 mm and about 620 kg / cm ² .

  Firing is preferably performed at 900 to 1300 ° C. in a reducing atmosphere for 1 to 24 hours.

  As the firing atmosphere at this time, a reducing atmosphere such as an argon gas, a nitrogen gas, a hydrogen sulfide gas, a nitrogen gas atmosphere containing a small amount of hydrogen gas, a carbon dioxide atmosphere containing carbon monoxide can be employed. Among these, firing is preferably performed in an inert gas atmosphere such as argon gas or nitrogen gas.

  When the firing temperature is less than 900 ° C., when carbonate is used as a raw material, the decomposition of carbon dioxide gas is insufficient, and the effect of diffusing Eu into the (Ca, Sr) S matrix cannot be obtained sufficiently. On the other hand, at a high temperature exceeding 1300 ° C., abnormal grain growth occurs and it becomes difficult to obtain uniform fine particles. In addition, if the firing time is less than 1 hour, it is difficult to obtain reproducibility of the material characteristics, and if it exceeds 24 hours, there is a problem of composition variation due to an increase in material scattering.

  Prior to the firing, temporary firing may be performed.

  At this time, the preliminary firing is performed, for example, by mixing the mixed powder at 600 ° C. to 1100 ° C. for 1 hour to 12 hours, in an inert gas atmosphere such as argon gas or nitrogen gas, a hydrogen atmosphere, a hydrogen sulfide atmosphere, an oxygen atmosphere, or an air atmosphere. What is necessary is just to bake.

  After calcination, the mixed powder may be further pulverized and mixed and fired so that the entire mixed powder becomes uniform.

  After firing, the particle size may be adjusted by pulverization and classification as required.

  Further, after firing or pulverization, annealing (annealing) may be performed as necessary. At this time, it is preferable that the annealing is performed at 400 to 1300 ° C. in an inert gas atmosphere such as argon gas or nitrogen gas, a hydrogen atmosphere, a hydrogen sulfide atmosphere, an oxygen atmosphere, or an air atmosphere.

(Use)
The red phosphor can be combined with a light source or an electron source that can excite the red phosphor to constitute a red light emitting element or device, and can be used for various applications. For example, the red phosphor and a light source that generates excitation light may be combined to form a red light emitting element or device. Alternatively, the red phosphor and an electron source that generates an electron beam may be combined to form red light. A light-emitting element or device can also be formed. In addition, a white light emitting element or device may be configured by combining a light source that generates excitation light, the red phosphor, and a blue to green phosphor, or an electron source that generates an electron beam and the red phosphor. A white light emitting element or device can also be configured by combining blue to green phosphors.

  Specifically, the red phosphor is disposed in the vicinity of the excitation light source or electron source (collectively referred to as “excitation source”) as described above, that is, in a position where the light emission or electron beam of the excitation source can be received. Thus, a red light emitting element or device can be configured. For example, a phosphor layer made of the red phosphor may be laminated on a light emitting layer made of a light emitter.

  At this time, the phosphor layer is prepared by, for example, adding the powdery red phosphor together with a binder to an appropriate solvent, thoroughly mixing and dispersing the obtained coating solution on the surface of the light emitting layer. What is necessary is just to form a coating film (phosphor layer) by apply | coating and drying.

  Alternatively, the phosphor layer can be formed by kneading the red phosphor in a glass composition and dispersing the phosphor of the present invention in the glass layer.

  Furthermore, the red phosphor may be formed into a sheet shape, and this sheet may be laminated on the phosphor layer, or the red phosphor may be directly sputtered onto the phosphor layer to form a film. You may do it.

  In the case of constituting a white light emitting element or apparatus, the powdery red phosphor and the powdery blue to green phosphor may be mixed, or the molded red phosphor. And a molded blue or green phosphor may be arranged.

  Examples are shown below, but the present invention is not construed as being limited thereto.

<Measurement of PL spectrum>
Using a spectrofluorimeter (F-4500, manufactured by Hitachi, Ltd.), using R928 manufactured by Hamamatsu Photonics as a photomultiplier, the region of 500 to 800 nm is corrected with a sub-standard light source (3000K), and a PL (photoluminescence) spectrum is obtained. It was measured.

<Measurement of CL spectrum>
A thin sample coated on an aluminum plate was placed in a high vacuum container with a pressure of 10 ^-5 Pa or less, and an electron beam accelerated with an acceleration voltage of 5 kV was irradiated from an electron gun to measure light emission from the sample. The electron gun used thermoelectrons emitted from a heated cathode.

(Preparation of In-added sample (1))
Using CaS, EuS, and In ₂ S ₃ as raw materials, the base material is weighed so that Eu: 1.0 mol%, and weighed so that the In amount is a predetermined amount between 0 and 4.0 mol%. These were mixed for 90 minutes by a paint shaker using zirconia balls having a diameter of 3 mm as media.

  Subsequently, it classified to 100 micrometers or less, and baked in 1050 degreeC for 12 hours in argon gas atmosphere, and obtained the red fluorescent substance (sample 1-8, 19-21).

  The In amount of Samples 1 to 8 is as shown in the margins of FIGS. 1 (A), (B) and FIGS. 2 (A) and 2 (B), and the In amount of Samples 19 to 21 is Sample 19: 0.05 mol%. Sample 20: 1.5 mol%, Sample 21: 2.5 mol%.

  About the obtained samples 1-8 and 19-21, CL spectrum (FIG. 1 (A) (B)) and PL spectrum (FIG. 2 (A) (B)) were measured.

(Preparation of In-added sample (2))
Using SrS, EuS, and In ₂ S ₃ as raw materials, the base material is weighed so that Eu is 1.0 mol%, and weighed so that the In amount is a predetermined amount between 0 and 10.0 mol%. These were mixed for 90 minutes by a paint shaker using zirconia balls having a diameter of 3 mm as media.

  Subsequently, it classified to 100 micrometers or less, and baked in argon gas atmosphere at 1050 degreeC for 12 hours, and obtained the red fluorescent substance (samples 22-31).

  The In amounts of Samples 22 to 28 are as shown in the margins of FIGS. 10 and 11, and the In amounts of Samples 29 to 31 are as follows: Sample 29: 0.05 mol%, Sample 30: 7.0 mol%, Sample 31: 10.0 mol%.

  About the obtained samples 22-28, CL spectrum (FIG. 10) and PL spectrum (FIG. 11) were measured.

(Preparation of Ga-added sample)
Using CaS, EuS, Ga ₂ S ₃ as raw materials, and weighing the base material so that Eu: 1.0 mol%, and weighing so that Ga is a predetermined amount between 0-4.0 mol%, These were mixed for 90 minutes in a paint shaker using zirconia balls having a diameter of 3 mm as media.

  Subsequently, it classified to 100 micrometers or less, and baked in 1050 degreeC for 12 hours in argon gas atmosphere, and obtained the red fluorescent substance (samples 9-13).

  The amounts of In in Samples 9 to 13 are as shown in the margins of FIGS. 3 and 4.

  About the obtained samples 9-13, CL spectrum (FIG. 3) and PL spectrum (FIG. 4) were measured.

(Preparation of Al-added sample)
Using CaS, EuS, Al ₂ S ₃ as raw materials, and weighing the base material so that Eu: 1.0 mol%, weighed so that Al is a predetermined amount between 0-4.0 mol%, These were mixed for 90 minutes in a paint shaker using zirconia balls having a diameter of 3 mm as media.

  Subsequently, it classified to 100 micrometers or less, and baked in 1050 degreeC for 12 hours in argon gas atmosphere, and obtained the red fluorescent substance (samples 14-18).

  The In amounts of Samples 14 to 18 are as shown in the margins of FIGS.

  About the obtained samples 14-18, CL spectrum (FIG. 5) and PL spectrum (FIG. 6) were measured.

  In addition, the above measurement results are summarized, and the relative red emission peak intensity when the addition amount of In, Ga, and Al and the PL relative intensity (red emission peak intensity without addition (maximum emission intensity) is set to 1) 7 and FIG. 12, the relative red color when the addition amount of In, Ga, and Al and the CL relative intensity (red emission peak intensity (maximum emission intensity) without addition is 1) are taken as 1. The relationship with the (emission peak intensity) is shown in FIGS.

  1 (A) and 1 (B), when In is blended, the emission peak near 400 nm (400 nm ± 30 nm) can be suppressed, and in particular, by blending 0.05 mol% or more of In, around 400 nm (400 nm ± It was found that the emission peak at 30 nm) can be eliminated, and at the same time, the red emission peak near 650 nm (650 nm ± 30 nm) becomes larger as the amount of added In increases.

  From FIG. 7, in the case of photoexcitation, by setting the In content to 0.05 to 2.5 mol%, the PL intensity can be increased compared to the case where In is not added, and the In content is reduced. By setting it as 0.1-1.5 mol%, PL intensity | strength can be raised 3 times or more compared with the case where In is not added, and also content of In shall be 0.2-1.0 mol%. As a result, it was found that the PL intensity can be increased by 5 times or more as compared with the case where In is not added.

  Moreover, when FIG. 12 is seen, by making content of In 0.05-2.5 mol%, especially 0.05-2.5 mol%, PL intensity is effective compared with the case where In is not added. Furthermore, by setting the In content to 0.1 to 1.5 mol%, particularly 0.1 to 1.0 mol%, the PL strength can be increased compared to the case where In is not added. It can be remarkably increased, and furthermore, by setting the In content to 0.2 to 1.0 mol%, particularly 0.2 to 0.5 mol%, the PL strength can be increased as compared with the case where In is not added. It has been found that it can be further enhanced.

  From FIG. 8, in the case of electron beam excitation, the CL intensity can be increased by setting the In content to 0.05 to 4.0 mol% as compared to the case where In is not added. By making the amount 0.1 to 2.0 mol%, it is possible to increase the CL strength more than twice compared with the case where In is not added, and further, the In content is 0.2 to 1.5 mol%. As a result, it was found that the CL intensity can be increased by 3 times or more compared to the case where In is not added.

  Moreover, when FIG. 13 is seen, CL intensity | strength can be raised compared with the case where In content is 0.05-4.0 mol% and In is not added, and In content is set to 0.00. By setting the content to 1 to 2.0 mol%, the CL strength can be further increased as compared with the case where In is not added, and the content of In is 0.2 to 2.0 mol%, particularly 0.2 to 2.0 mol%. It was found that the CL strength can be further increased by setting it to 1.5 mol% as compared with the case where In is not added.

  In addition, although the said test result is the fluorescent substance which made CaS: Eu or SrS: Eu a base | substrate, and doped In to this, (Ca and Sr) S: Eu was made into a base substance, and this was doped with In. It is considered that the same applies to

(Test Example 1)
Using CaS, SrS, and EuF ₃ as raw materials, and weighing the base material so that Eu: 1.0 mol%, the content ratio of Ca and Sr was changed at that time (Ca _1-x Sr _x ) S : Weighed so as to change the x value of the red phosphor represented by Eu (0 ≦ x ≦ 1), and mixed for 90 minutes with a paint shaker using zirconia balls of φ3 mm as media.

  Subsequently, it classified to 100 micrometers or less, and baked in argon gas atmosphere at 1050 degreeC for 12 hours, and obtained red fluorescent substance.

  FIG. 9 shows the result of measuring the PL spectrum of the obtained red phosphor.

  From the results of FIG. 9, the emission peak wavelength of CaS: Eu is 650 nm, the emission peak wavelength of SrS: Eu is 590 nm, and the emission wavelength is adjusted between the emission wavelengths by adjusting the amounts of calcium and strontium. It was found that it can be controlled arbitrarily.

Such an effect when the x value is changed is due to the fact that the red phosphor of the present invention, that is, the general formula: (Ca _1−x Sr _x ) S: Eu, In (where x is 0 to 1) The same applies to the red phosphors indicated by.

Claims (10)

A general formula: (Ca _1-x Sr _x ) S: Eu, In (wherein x is 0 to 1), a red phosphor containing 0.1 to 5 mol% of Eu , A red phosphor containing 0.05 to 4.0 mol% of In with respect to the total number of moles of Ca and Sr. The red phosphor according to claim 1, containing 0.5 to 5 mol% of Eu . A red phosphor having a general formula: CaS: Eu, In, containing 0.1 to 5 mol% of Eu, and containing 0.05 to 4.0 mol% of In with respect to the number of moles of Ca The red phosphor according to claim 1 or 2 . A red phosphor represented by the general formula: SrS: Eu, In, containing 0.1 to 5 mol% of Eu, and containing 0.05 to 4.0 mol% of In with respect to the number of moles of Sr The red phosphor according to claim 1 or 2 . The red phosphor according to any one of claims 1 to 4 , wherein the red phosphor for photoexcitation contains 0.05 to 2.5 mol% of In with respect to the total number of moles of Ca and Sr. . A red light emitting device or apparatus comprising a light source that generates excitation light and the red phosphor according to claim 5 . A white light emitting element or device comprising: a light source that generates excitation light; the red phosphor according to claim 5 ; and a blue to green phosphor. The red phosphor according to any one of claims 1 to 4 , wherein the red phosphor for electron beam excitation contains 0.05 to 4.0 mol% of In with respect to the total number of moles of Ca and Sr. Phosphor. A red light emitting element or device comprising an electron source that generates an electron beam and the red phosphor according to claim 8 . A white light emitting device or apparatus comprising: an electron source that generates an electron beam; the red phosphor according to claim 8 ; and a blue to green phosphor.

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