JP3937622B2 - Phosphor production container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fluorescent body manufacturing containers that can produce a good crystallinity phosphor.
[0002]
[Prior art]
In recent years, GaN has been known as a material that emits blue and green high luminance light emitting elements such as LEDs and LDs in the case of a single crystal. Conventionally, in order to manufacture a GaN phosphor, a Ga compound as a raw material is mixed with a compound of a doping material, and this is placed in a firing furnace and baked at a high temperature while flowing ammonia to nitride and Ga. Dope material.
[0003]
There have been attempts in the past to emit light from the material thus obtained with an electron beam, but no practical luminance has been achieved with respect to a phosphor in powder form.
[0004]
[Problems to be solved by the invention]
Unlike the other phosphor materials, the biggest reason why the luminance cannot be obtained is difficulty in nitriding. That is, since this material has a small difference between the nitriding temperature (700 ° C. to 1000 ° C.) and the temperature at which decomposition starts (950 ° C. or more), nitriding and decomposition are likely to proceed simultaneously in a normal heating reaction. For this reason, GaN can be produced, but white and highly crystalline GaN that can be used as a phosphor could not be produced.
[0005]
In order to manufacture a GaN phosphor, as described above, the raw material is generally baked at a high temperature while flowing a gas containing ammonia or nitrogen in a tubular furnace. Since it is consumed, a sufficient amount of ammonia must be supplied into the tube furnace for the synthesis of GaN.
[0006]
At this time, the raw material 101 is placed in a conventional box-shaped container 100 (generally referred to as a boat) as shown in FIGS. 5 and 6, and this is placed in a tubular furnace and fired while flowing ammonia. However, a uniform nitriding reaction could not be obtained. This is because the box-shaped boat 100 is open only on the top surface and has walls on all four sides, and as shown by arrows in FIGS. 5 and 6, the wall 102 intersecting the direction in which ammonia flows is a gas. This is considered to be because the GaN nitridation reaction is performed unevenly.
[0007]
For this reason, even if it is the GaN fluorescent substance in the same batch, the fluorescent substance from which temporary light emission is obtained is a very small part, and the emitted light intensity was low enough to be unpractical. In addition, the reproducibility of production of the GaN phosphor is not desirable, and a GaN phosphor having high emission intensity and stable characteristics cannot be obtained.
[0008]
The present invention provides a phosphor manufacturing container that can be applied to a phosphor manufacturing method performed by flowing a gas into a tubular furnace in which a phosphor material is arranged, and that can manufacture a phosphor having excellent characteristics. It is an object.
[0009]
[Means for Solving the Problems]
The phosphor manufacturing container according to claim 1 stores the phosphor material material, and the tube body of the tubular furnace is provided with a heating means in a tube body in which a gas flows along a predetermined direction. In the phosphor manufacturing container that is arranged in the gas and heated in the gas atmosphere of the gas that flows along a predetermined direction, there are no members that obstruct the gas flow because both ends of the gas flow direction are open. It is characterized by the shape of a cylinder cut by a cutting plane parallel to the axis .
[0012]
The phosphor manufacturing container described in claim 2 is the phosphor manufacturing container according to claim 1 , wherein the radius of the cylinder is substantially the same as the radius of the tube.
[0013]
The phosphor manufacturing container according to claim 3 is the phosphor manufacturing container according to claim 1, wherein the curvature of the cylinder is substantially the same as the curvature of the tubular body, and when inserted into the tubular passage, It is characterized by being in a state close to the inner peripheral surface of the tubular path .
[0014]
DETAILED DESCRIPTION OF THE INVENTION
In order to solve the above-mentioned problems, a boat (phosphor manufacturing vessel) having a structure that does not obstruct the gas flow in the tubular furnace so that the gas sufficiently contacts the raw material of the GaN phosphor. The present inventors considered that it is important to store the raw material and perform firing in a tubular furnace. As a specific method, a boat used for firing a GaN phosphor in a tubular furnace is formed into a shape having no edges at both ends in the gas flow direction. Thereby, the flow of ammonia gas becomes smooth, and a large amount of ammonia can be supplied to the raw material of the GaN phosphor. As a result, the reactivity at the time of GaN phosphor synthesis is improved, and a GaN phosphor with uniform emission characteristics can be synthesized. In addition, the reproducibility of the synthesis is improved, and a stable quality GaN phosphor can be produced.
[0015]
【Example】
(1) Example 1
A method for producing a GaN: Zn phosphor will be described. A Ga compound such as Ga ₂ O ₃ or Ga ₂ S ₃ is used as a base material of the phosphor, and a Zn compound is used as a doping material. Specifically, ₃ g of Ga ₂ O ₃ and 0.6 g of ZnS as a Zn doping material are mixed well and placed on a firing boat.
[0016]
The firing boat 1 has a structure as shown in FIGS. The firing boat 1 has a shape in which a cylinder having both ends opened is divided into two along the axial direction. The curvature of the firing boat 1 is substantially the same as the curvature of the tubular furnace 2, and when the firing boat 1 is inserted into the tubular furnace 2, the firing boat 1 is in a state close to the inner peripheral surface of the tubular furnace 2. Since both ends of the firing boat 1 are open and there is no member that obstructs the flow of ammonia gas, the ammonia gas flowing in the tubular furnace 2 is sufficiently spread and contacts the raw material 3 placed on the firing boat 1. Further, since the firing boat 1 is close to the inner peripheral surface of the tubular furnace 2, heat from the heater 4 disposed around the tubular furnace 2 is efficiently transmitted to the firing boat 1 to synthesize phosphors. More efficiently. Quartz, alumina, carbon, boron nitride or the like is used as the material of the firing boat 1. In addition, since the curvature of the firing boat 1 and the tubular furnace 2 is substantially the same, the firing boat 1 is stably disposed in the tubular furnace 2, and the operability during loading and unloading is good and easy to handle.
[0017]
The raw material 3 is placed on the firing boat 1 and placed in the tubular furnace 2. In this state, the raw material was baked at 1150 ° C. for 2 hours while flowing ammonia at 350 ml / min to obtain a granular GaN phosphor. The obtained GaN phosphor was applied to the anode conductor of the anode substrate of the fluorescent arc tube, and evaluated by emitting light at an anode voltage of 30V. Furthermore, it applied to the anode conductor of the anode board | substrate of the field emission type light emitting element (Field Emission Display), and made it light-emit by the anode voltage 400V, and evaluated.
[0018]
When PL (photoluminescence) was confirmed for the GaN phosphor on the firing boat 1 using a 365 nm ultraviolet lamp, there was no intensity of partial light emission and uniform blue light emission was obtained.
[0019]
For comparison, synthesis was performed using a firing boat 100 having a general shape as shown in FIG. 5. As shown by arrows in FIG. The phosphor obtained because of non-uniformity has a low emission intensity, and a portion that does not emit light is also generated.
[0020]
FIG. 4 shows the results of comparison of light emission characteristics of a GaN phosphor synthesized using a conventional boat and a GaN phosphor synthesized using the boat of the present application. As shown in FIG. 4, according to the firing boat 1 of this example, the light emission characteristics (luminance characteristics) of the obtained phosphor were improved more than twice as compared with those obtained by the conventional firing boat.
[0021]
(2) Example 2
A method for producing a GaInN: Mg phosphor will be described. ₂ g of Ga ₂ S ₃ , 1 g of In ₂ S ₃ and 0.4 g of MgCl are mixed well, placed on a firing boat 1 having the same structure as in Example 1, and synthesized in the same tubular furnace 2. The raw material was fired at 1100 ° C. for 3 hours while flowing ammonia in the tubular furnace 2 at 350 ml / min to obtain a granular GaInN: Mg phosphor. When GaInN was confirmed to have PL by an ultraviolet lamp, uniform green light emission was obtained with no partial light emission intensity. When evaluated with a fluorescent light emitting tube or a field emission type light emitting device FED in the same manner as in Example 1, green light emission was obtained.
[0022]
The embodiment described above relates to the manufacture of a Ga _{1 -X} In _X N: A, B (0 ≦ X <1, A = Zn, Mg, B = Si, Ge) phosphor. The fired boat 1 can be used for manufacturing other phosphors.
[0023]
(3) Example 3
As an example when the present invention is applied to a phosphor other than GaN, a case where a ZnGa ₂ O ₄ phosphor is fabricated will be described.
As raw materials, 8.1 g of ZnO, 18.7 g of Ga ₂ O ₃ and 5.79 g of Li ₃ PO ₄ are mixed well and subjected to primary firing at 1200 ° C. for 3 hours in the atmosphere with an alumina crucible. A sample obtained by pulverizing and acid-cleaning the primary fired sample is placed on a fired boat having the same structure as in Example 1, and secondary fired in the same tubular furnace 2. A ZnGa ₂ O ₄ phosphor was obtained by firing for 1 hour at 1100 ° C. while flowing H ₂ gas at 40 ml / min and N ₂ gas at 160 ml / min in a tubular furnace. When the PL of ZnGa ₂ O ₄ was confirmed by an ultraviolet lamp, uniform blue light emission was obtained with no intensity of partial light emission. When evaluated with a fluorescent light emitting tube or a field emission type light emitting device in the same manner as in Example 1, blue light emission was obtained.
[0024]
As described above, the firing boat of the present invention is useful as a container for storing a raw material in a method of synthesizing a phosphor by flowing a gas and bringing it into contact with the raw material.
[0025]
【The invention's effect】
According to the phosphor manufacturing container (baking boat) or the phosphor manufacturing apparatus using the same according to the present invention, the following effects are obtained in the synthesis of the phosphor performed by firing the raw material while flowing the gas. It is done.
[0026]
1. Since a large amount of gas can be brought into contact with the phosphor raw material at the time of producing the phosphor, the reaction is promoted and the crystallinity of the obtained granular phosphor is increased.
[0027]
2. Since the gas flows uniformly in the vicinity of the phosphor raw material, a uniform phosphor having no uneven light emission can be obtained.
[0028]
3. The reproducibility of the phosphor production is improved.
[0029]
4). Therefore, a phosphor with high emission intensity can be produced with good reproducibility.
[0030]
According to the phosphor production container (firing boat 1) or the phosphor production apparatus using the same according to the present invention, the following effects can be obtained particularly in the production of a GaN phosphor.
[0031]
(1). When a GaN phosphor is produced, a large amount of ammonia can be brought into contact with the GaN raw material, so that the nitriding reaction is promoted and the crystallinity is increased.
[0032]
(2). Since ammonia in the vicinity of GaN flows uniformly, a uniform GaN phosphor without partial light emission unevenness can be obtained.
[0033]
(3). The repeated reproducibility of GaN phosphor production is improved.
[0034]
(4). For this reason, it becomes possible to produce a GaN phosphor with high emission intensity with good reproducibility.
[Brief description of the drawings]
FIG. 1 is a partially cutaway perspective view showing an example of an embodiment of the present invention.
FIG. 2 is a cross-sectional view in a cross section orthogonal to the axis of the tubular furnace 2 in an example of an embodiment of the present invention.
FIG. 3 is a plan view of a firing boat 1 in an example of an embodiment of the present invention.
FIG. 4 is a diagram showing a result of comparison of light emission characteristics of a GaN phosphor synthesized using a conventional boat and a GaN phosphor synthesized using the boat of the present application.
FIG. 5 is a perspective view showing a method of manufacturing a phosphor using a conventional boat.
FIG. 6 is a plan view showing a method of manufacturing a phosphor using a conventional boat.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Firing boat as a phosphor manufacturing vessel, 2 ... Tubular furnace, 3 ... Phosphor raw material (gallium oxide, etc., raw material for GaN phosphor)

Claims (3)

The phosphor material material is stored in the tube body of the tubular furnace in which the heating means is provided in the tube body in which the gas flows in a predetermined direction, and the gas flowing in the predetermined direction is placed in the tube body. In a phosphor manufacturing container heated in a gas atmosphere,
A phosphor manufacturing container having a shape obtained by cutting a cylinder that is open at both ends in the gas flow direction and has no member that obstructs the gas flow, along a cutting plane parallel to the axis. Radius substantially phosphor manufacturing container according to claim 1, wherein the same radius the tube of the cylinder. 2. The phosphor manufacturing container according to claim 1, wherein a curvature of the cylinder is substantially the same as a curvature of the tubular body, and when the cylinder is inserted into the tubular path, the cylinder is brought into a state of being close to the inner peripheral surface of the tubular path.

Images