JP2007070207A - Group 13 nitride crystal particle, method for producing the same, and fluorescent material using the particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing group 13 nitride crystal particles by which surface modification suitable for mass production can be efficiently carried out compared to the prior art; the group 13 nitride crystal particles obtained by the same; and a fluorescent material using the same. <P>SOLUTION: The method for producing the group 13 nitride crystal particles includes a process for obtaining a precursor by reacting a dialdehyde with an organic compound having an amino group, a process for obtaining a complex having a structure similar to carbene by reacting the precursor with a halide of a group 13 element, and a process for obtaining the group 13 nitride crystal particles by heat treating the complex having the structure similar to carbene. The each crystal particle contains a bond of the group 13 element and nitrogen, and in each particle, any of an aliphatic cyclic hydrocarbon group, a linear alkyl group having at least four carbon atoms and an aromatic hydrocarbon group is chemically bonded to the nitrogen as modification molecule. The fluorescent material is produced by using the crystal particles. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a group 13 nitride crystal particle, a method for producing the same, and a phosphor using the same.

  A technique is known in which a modifying molecule having a specific function is fixed on the surface of the crystal grain to improve the characteristics of the crystal grain or give a new function.

  For example, Patent Document 1 provides functions such as solvent resistance, dispersibility, and insulation by partially covering the surface of the substrate particles with an organic polymer composed of a metathesis polymerizable monomer. It has been shown that.

  As an application example of crystal particles, nanoparticle phosphors that control the band gap by the quantum size effect of nanosized semiconductor particles and obtain a desired emission color are known. In recent years, the development of nanoparticle phosphors using group 13 nitride semiconductors has been proposed because of safety and environmental aspects, or because light emission can be expected to be more efficient than before.

Also in the field of nanoparticle phosphors, surface modification is an important technique for imparting and improving new functions. For example, Patent Document 2 has surface-modified molecules generated by reaction in the gas phase or plasma. It has been shown that group 13 nitride semiconductor nanoparticles are excellent in dispersibility and affinity in an organic medium substrate.
JP 2003-313459 A JP 2004-307679 A

  Since the group 13 nitride semiconductor nanoparticle fluorescent material of Patent Document 2 is generated by reaction in a gas phase or plasma, the purity is high and the particle size distribution is narrow. For this reason, the light emission characteristics are uniform and highly efficient.

  On the other hand, in the production of nanoparticles by gas phase or plasma reaction, the utilization efficiency of raw materials is low, and a large and complicated manufacturing apparatus is required, so that mass production is difficult at low cost.

  However, for crystal growth of nitride semiconductors, high temperature and non-equilibrium growth conditions are indispensable due to the chemical stability of the material, and no efficient production method has been established other than the production method by the above gas phase or plasma reaction. It was. Furthermore, a surface modification method suitable for mass production has not been established.

  The present invention has been made in order to solve the above-described problems, and its object is to provide a group 13 nitride that is more efficient than the prior art and can be subjected to surface modification suitable for mass production. The object is to provide a method for producing crystal particles, the obtained group 13 nitride crystal particles, and a phosphor using the crystal particles.

  The present invention includes a step of obtaining a precursor by reacting an organic compound having an amino group with a dialdehyde, a step of reacting the precursor with a group 13 element halide to obtain a carbene-like structure complex, and the carbene-like structure. And a step of obtaining a group 13 nitride crystal particle by heat-treating the complex.

Here, the dialdehyde is preferably glyoxal.
In the method for producing a group 13 nitride crystal particle of the present invention, the organic compound having an amino group is preferably at least one of the following (1) to (3).

(1) Aliphatic cyclic hydrocarbon having an amino group (more preferably, cyclohexylamine)
(2) C4 or more aliphatic chain hydrocarbon having an amino group (more preferably, tertiary butylamine)
(3) Aromatic hydrocarbon having an amino group (more preferably, 2,6-diisopropylaniline)
In the method for producing a group 13 nitride crystal particle of the present invention, the heat treatment is preferably performed by adding at least one of ammonia, urea, and hydrazine.

  In the method for producing a group 13 nitride crystal particle of the present invention, when the group 13 element halide is a group 13 element iodide, the heat treatment is preferably performed at 400 ° C. or lower.

  The present invention also provides a crystal particle containing a bond of a group 13 element and nitrogen, wherein the modifying molecule is an aliphatic cyclic hydrocarbon group, an aliphatic chain hydrocarbon group having 4 or more carbon atoms, or an aromatic hydrocarbon group. Provided is a group 13 nitride crystal particle in which at least one is chemically bonded to the nitrogen.

  In the group 13 nitride crystal particle of the present invention, the modifying molecule preferably contains at least one of a cyclohexyl group, a tertiary butyl group, and a 2,6-diisopropylphenyl group.

  The present invention also provides a phosphor using the group 13 nitride crystal particles of the present invention described above.

  INDUSTRIAL APPLICABILITY According to the present invention, a method for producing a group 13 nitride crystal particle that is more efficient than conventional and can be subjected to surface modification suitable for mass production, the obtained group 13 nitride crystal particle, and the crystal A phosphor using the particles can be provided.

  The method for producing Group 13 nitride crystal particles of the present invention includes [1] a step of obtaining a precursor by reacting an organic compound having an amino group with a dialdehyde (hereinafter referred to as “precursor forming step”). [2] a step of reacting the precursor with a group 13 element halide to obtain a carbene-like structure complex (hereinafter referred to as “complex formation step”); and [3] heat treatment of the carbene-like structure complex. And a step of obtaining a group 13 nitride crystal particle (hereinafter referred to as a “crystal particle forming step”). Hereinafter, each process is explained in full detail.

[1] Precursor formation step First, in the precursor formation step, a dialdehyde is reacted with an organic compound having an amino group to form a precursor. The dialdehyde used in the present invention is not particularly limited as long as it is a compound having two aldehyde groups. For example, glyoxal (oxalic acid dialdehyde), succinic acid dialdehyde, malonic acid dialdehyde, glutar Examples include aldehyde and dialdehyde cellulose. Among them, it is preferable to use glyoxal as a dialdehyde because it is easily coordinated to a group 13 element and has the highest yield of the complex in the step [2] complex formation described below.

  The organic compound having an amino group used in the present invention is not particularly limited, and is an aliphatic cyclic hydrocarbon having an amino group, an aliphatic chain hydrocarbon having 4 or more carbon atoms having an amino group, amino An aromatic hydrocarbon having a group, an organometallic compound having an amino group, an organic halide having an amino group, an amino acid, and the like can be used. Among them, from the viewpoint of facilitating the control of the particle size of the crystal particles, those having a relatively large molecular weight and more bulky are suitable, so that the aliphatic cyclic hydrocarbon having an amino group, the number of carbons having an amino group It is preferable to use 4 or more aliphatic chain hydrocarbons or aromatic hydrocarbons having amino groups.

  The aliphatic cyclic hydrocarbon having an amino group may be either saturated or unsaturated, and specifically includes cyclopropylamine, cyclobutylamine, cyclohexylamine, cyclopentylamine, cyclooctylamine, cyclododecylamine, and the like. Can be mentioned. Moreover, you may use the aliphatic cyclic hydrocarbon which further contains substituents (for example, an alkyl group, an alkylene group, an imino group, a hydroxy group, a nitro group etc.) other than an amino group. Among these, cyclohexylamine is particularly preferable from the viewpoint of a compound having a high molecular weight having high reactivity and high reaction stability.

  The aliphatic chain hydrocarbon having 4 or more carbon atoms having an amino group may be linear or molecular chain, and may be saturated or unsaturated. Note that when an aliphatic chain hydrocarbon having an amino group and having 3 or less carbon atoms is used, there is a problem that the complex synthesis reaction is difficult to proceed because of low reactivity. Further, if the reactivity becomes too high, the risk of the production process increases and the cost also increases. Therefore, it is preferable to use an aliphatic chain hydrocarbon having an amino group having 12 or less carbon atoms.

  Specific examples of the aliphatic chain hydrocarbon having 4 or more carbon atoms having an amino group include normal butylamine, isobutylamine, tertiary butylamine, normal pentylamine, isopentylamine, hexylamine, stearylamine, octylamine, diamino Examples include hexane, diaminopentane, diaminobutane, dibenzylamine, and diisopropylamine. Further, an aliphatic cyclic hydrocarbon having 4 or more carbon atoms further containing a substituent other than an amino group (for example, an alkyl group, an alkylene group, an imino group, a hydroxy group, a nitro group, etc.) may be used. Of these, tertiary butylamine is particularly preferred from the viewpoint of reaction stability.

  Specific examples of the aromatic hydrocarbon having an amino group include aniline, methylaniline, dimethylaniline, toluidine, quinoline, aminoindane, anisidine, and phenetidine. Moreover, you may use the aromatic hydrocarbon which further contains substituents (for example, an alkyl group, an alkylene group, an imino group, a hydroxy group, a nitro group etc.) other than an amino group. Among these, 2,6-diisopropylaniline is particularly preferable from the viewpoint of a compound having a large molecular weight having high reactivity and high reaction stability.

  In the precursor formation step, the dialdehyde and the organic compound having an amino group are preferably 1: 1 to 1:10 (substance ratio), more preferably 1: 2 to 1: 5 (substance ratio). It is preferable to make it react so that it may become. This is because dialdehyde: organic compound having an amino group = less than 1: 1, dialdehyde becomes excessive and the reaction tends to be inhibited, and dialdehyde: organic compound having an amino group = 1:10. This is because the organic compound having an amino group becomes excessive and the reaction tends to be inhibited.

  The reaction conditions in the precursor forming step can be appropriately set depending on the combination of materials to be used, the total amount of raw materials, the size and material of the reaction vessel to be used, etc., preferably −10 to 25 ° C., more preferably 0 to 10 ° C. Perform the reaction in the range. This is because if the temperature is lower than −10 ° C., the reaction tends to hardly proceed, and if the temperature exceeds 25 ° C., the reaction proceeds excessively and the raw materials tend to volatilize easily. The reaction time is usually about 3 to 24 hours.

  All the precursors obtained in this step form a chelate ligand having an imide bond. Below, the reaction scheme at the time of making glyoxal and cyclohexylamine react is illustrated, for example.

[2] Complex formation step In the subsequent [2] complex formation step, a group 13 element halide is reacted with the precursor obtained in the above-mentioned [1] precursor formation step. Here, the “Group 13 element” refers to an element that is also called Group IIIB, including B, Al, Ga, In, and Tl. The “group 13 element halide” refers to a halide of the above group 13 element. Specifically, BF ₃ , GaF ₃ , GaF, InF ₃ , InF, AlF ₃ , TlF ₃ , TlF, BCl ₃ , _{GaCl 3, GaCl, InCl 3,} InCl, AlCl 3, TlCl 3, TlCl, BBr 3, GaBr 3, GaBr, InBr 3, InBr, AlBr 3, TlBr 3, TlBr, BI 3, GaI 3, GaI, InI 3, InI, AlI ₃ , TlI ₃ , TlI and the like can be mentioned. Among these, GaCl ₃ , InCl ₃ , AlCl ₃ , GaI, InI, and AlI ₃ are used as group 13 element halides from the viewpoints of reaction stability, raw material costs, and industrial utility of the group 13 nitride crystal to be synthesized. Is preferred.

  In the complex formation step, the precursor and the group 13 element halide are preferably 1: 1 to 1:10 (substance ratio), more preferably 1: 2 to 1: 5 (substance ratio). It is preferable to make it react. When the precursor: group 13 element halide is less than 1: 1, the group 13 element halide becomes excessive, and the reaction tends to be inhibited. The precursor: group 13 element halide = 1. This is because when it exceeds 10, the precursor becomes excessive and the reaction tends to be inhibited.

  The reaction conditions in the complex formation step can be appropriately set depending on the combination of materials to be used, the total amount of raw materials, the size and material of the reaction vessel to be used, etc., preferably 0 to 30 ° C., more preferably 10 to 25 ° C. Perform the reaction. This is because if the temperature is less than 0 ° C., the reaction tends to hardly proceed, and if the temperature exceeds 30 ° C., the reaction proceeds excessively and the raw materials tend to volatilize easily. The reaction time is usually about 3 to 24 hours.

A carbene-like structure complex is formed by reacting the above-mentioned group 13 element halide with the precursor. Hereinafter, a reaction scheme in the case where gallium trichloride (GaCl ₃ ) is reacted with a precursor obtained by reacting glyoxal with cyclohexylamine is shown.

  Here, the “carbene-like structure complex” in this specification has a structure similar to a carbene complex in which the nitrogen atom of the chelate ligand is bidentate to a group 13 element, as shown below. Defined as a complex.

[3] Crystal Particle Formation Step In the subsequent [3] crystal particle formation step, the carbene-like structure complex obtained in the above-mentioned [2] complex formation step is heat-treated to obtain group 13 nitride crystal particles. It is preferable to perform the heat processing in the said process within the temperature range of 200-500 degreeC, and it is more preferable to carry out within the temperature range of 250-450 degreeC. When the heating temperature is less than 200 ° C., crystallization tends not to be promoted sufficiently, and when the heating temperature exceeds 500 ° C., the carbene skeleton of the complex tends to be broken, and the desired chemical reaction is not promoted. It is because it is in a tendency. Note that when iodide is used as the group 13 element halide, heat treatment is performed at 400 ° C. or lower (more preferably, 200 to 300 ° C.) because the reactivity is high and the carbene skeleton may be destroyed. Is preferred. Further, the heat treatment may be performed under pressure using an autoclave or the like.

  In the crystal particle forming step, it is preferable to add the nitrogen-containing compound and perform the heat treatment in order to compensate for the deficiency of nitrogen. Examples of nitrogen-containing compounds include ammonia, urea, hydrazine, organic compounds having substituents containing nitrogen (for example, amino groups, imino groups, nitro groups, etc.), azo compounds, etc. Among them, reaction stability and From the viewpoint of the cost of raw materials, it is preferable to add ammonia, urea or hydrazine.

  The addition amount of the nitrogen-containing compound is not particularly limited, but the carbene-like structure complex and the nitrogen-containing compound are preferably in the range of 1: 0.01 to 10 (substance ratio), and 1: 0. It is more preferable that it is 1-1 (substance quantity ratio). This is because carbene-like structure complex: nitrogen-containing compound = 1: below 1: 0.01, the effect of complementing nitrogen deficiency tends to be poor. If the carbene-like structure complex: nitrogen-containing compound exceeds 1:10, the material utilization efficiency is poor, the nitrogen compound becomes excessive and the reaction is inhibited, and the reaction vessel tends to corrode easily. is there.

  In the crystal particle forming step, the carbene-like structure complex obtained in the above-mentioned [2] complex forming step is heat-treated to cause a bond between the group 13 element and nitrogen, and the group 13 nitride crystal particle is converted into fine particles. Precipitate. Here, since the carbene-like structure complex has high reactivity, it has an advantage that group 13 nitride crystal particles can be synthesized at a lower temperature than vapor phase growth. Further, since the carbene-like structure complex has a coordination bond between Ga and N, there is an advantage that the proportion of raw material that is wasted without being reacted is remarkably smaller than that of conventional vapor phase growth.

  In addition, an aliphatic cyclic hydrocarbon group derived from an organic compound having an amino group, an aliphatic chain hydrocarbon group having 4 or more carbon atoms, an aromatic hydrocarbon residue, or the like, which becomes a chelate residue in the present invention, is a nitride. Residues having a function of controlling the particle size during crystal formation and having a large molecular weight and bulky hinder the increase in the crystal of the group 13 nitride, so that there is an advantage that the particle size can be kept small. In addition, a residue having a large molecular weight has an advantage that crystallization occurs even at a low temperature because it promotes a chemical reaction.

  The present invention is a crystal particle containing a bond between a group 13 element and nitrogen, and includes at least an aliphatic cyclic hydrocarbon group, an aliphatic chain hydrocarbon group having 4 or more carbon atoms, or an aromatic hydrocarbon group as a modifying molecule. Group 13 nitride crystal grains, any of which are chemically bonded to the nitrogen, are also provided. Such a group 13 nitride crystal particle of the present invention is manufactured by the above-described method for manufacturing a group 13 nitride crystal particle of the present invention, but is manufactured by other methods. However, it is preferably produced by the above-described method for producing a group 13 nitride crystal particle of the present invention.

  The group 13 nitride particles of the present invention contain a bond between nitrogen and at least one group 13 element selected from B, Al, Ga, In, and Tl as described above. The bond between the group 13 element and nitrogen is, for example, X-ray microanalyzer method (EPMA) or X-ray photoelectron spectroscopy (XPS) in which vibration energy of the chemical bond is measured by infrared absorption (IR, FTIR method). Thus, the chemical shift can be measured from the group 13 nitride crystal particles.

  In addition, the group 13 nitride crystal particles of the present invention have at least one of a saturated aliphatic cyclic hydrocarbon group, an aliphatic chain hydrocarbon group having 4 or more carbon atoms, and an aromatic hydrocarbon group as a modifying molecule. It is characterized by being connected. Such a modifying molecule is a chelate residue derived from an organic compound having an amino group when the group 13 nitride crystal particle is produced by the method for producing a group 13 nitride crystal particle of the present invention described above. Formed by part of the group. That is, such a chelate residue is firmly bonded to the crystal particle and functions as a modifying molecule because it is chemically bonded to nitrogen of the crystal particle even after the group 13 nitride crystal particle of the present invention is formed. .

  The group 13 nitride crystal particles of the present invention are formed by adhering the above-mentioned modifying molecules, so that organic solvents (for example, acetone, ethyl alcohol, methyl alcohol, xylene, toluene, isopropyl alcohol, polyvinyl alcohol, ethylene glycol, hexamethylene) Glycol) and resins (for example, epoxy, acrylic, silicon, phenol, polycarbonate, polypropylene, melamine, polyimide, polyamide), and the like have high affinity. In addition, the group 13 nitride crystal particles of the present invention have high dispersibility in the above-described organic solvent and resin because the modifying molecule is fixed. In addition, since the modifying molecule is fixed to prevent the group 13 nitride crystal particles from aggregating, the uniformity of the filler is improved when the crystal particles are used as a filler.

  In the group 13 nitride crystal particle of the present invention, the modifying molecule preferably contains at least one of a cyclohexyl group, a tertiary butyl group, and a 2,6-diisopropylphenyl group.

The group 13 nitride crystal particles of the present invention may contain unintended impurities. If the concentration is low, at least one of group 2 elements (Be, Mg, Ca, Sr, Ba), Zn or Si is used as a dopant. Any of these may be added intentionally. The concentration range is preferably 1 × 10 ¹⁶ cm ⁻³ to 1 × 10 ²¹ cm ⁻³ from the viewpoint of controlling electrical characteristics and optical properties due to valence electrons, and 1 × 10 ¹⁷ cm ⁻³ to 1 × 10 ¹⁹ cm ^{−. 3} is more preferable. Particularly suitable dopants include Mg, Zn, and Si because they are likely to be donors or acceptors that form appropriate impurity level energy in the group 13 nitride.

Of the group 13 nitride crystal particles of the present invention, the portion composed of a group 13 element and nitrogen is a single composition particle (for example, GaN, AlN, InN) composed of a single group 13 element and nitrogen. may be, mixed crystal particles comprising a plurality of 13 group element and nitrogen _{(e.g., in x Ga 1-x N} , Al x Ga 1-x N, in Al _x in _y IGa _z N (where, 0 <x <1, 0 <y <1, x + y + z = 1)). Further, a layer having a bond of a group 13 element and nitrogen is provided on the outside, and materials having different compositions (for example, oxide particles of group 13 elements such as Ga ₂ O ₃ and In ₂ S ₃₎ It may have a laminated structure including sulfide particles, semiconductor particles such as ZnO, SiC, and ZnS, group 13 elements such as Ga, In, Al, Au, Pt, and Ni, or other metal particles. In the case of having the above laminated structure, the modifying molecule is chemically bonded to nitrogen contained in the outer layer. The group 13 nitride crystal particles having such a laminated structure are formed, for example, by forming a carbene-like structure complex in which different precursors are coordinated to a plurality of group 13 elements in the complex formation step, and forming these into crystal particles. What is necessary is just to heat-process in the same reaction container at a process. Since the optimum reaction temperature differs depending on the structure of the carbene structure-like complex, the laminated structure grows by temperature control. Alternatively, if the material fine particles having a different composition are placed in the same reaction vessel as the carbene-like structure and subjected to heat treatment, crystal particle formation proceeds with the material fine particles having the different composition as nuclei.

  The present invention also provides a phosphor using the group 13 nitride crystal particles of the present invention described above. As described above, the group 13 nitride crystal particles of the present invention are formed by chemically bonding nitrogen and the modifying molecule to fix the modifying molecule, thereby improving the dispersibility and affinity described above. In addition, the effect of covering crystal defects on the particle surface is also exhibited. Furthermore, since the modifying molecule also has a function of absorbing excitation light energy and transferring it to the group 13 nitride, the light emission efficiency is improved.

  In the phosphor of the present invention, when the group 13 nitride crystal particles of the present invention are formed as a single particle as described above, the portion having a bond between the group 13 element and nitrogen is used as a core, and the modified molecule Can function as a shell. Two or more layers of shells may be formed. In this case, the first shell, the second shell,... Are called from the inner shell side. In this case, the group 13 nitride crystal particles having the above-described laminated structure can be made to function as each shell in order as the innermost portion is the core and the other portions including the modifying molecules are directed outward. . Further, the shell does not need to include the entire inner shell, and the distribution may be present only in layers other than the core.

  The band gap of the phosphor core using the crystal particles is preferably in the range of 1.8 to 2.8 eV. When used as a red phosphor, 1.85 to 2.5 eV is used as a green phosphor. In the case of 2.3 to 2.5 eV in the case, the range of 2.65 to 2.8 eV is particularly preferable when used as a blue phosphor. The band gap of the shell is preferably larger than the core. The band gap can be adjusted within the above range by changing the composition ratio of the group 13 elements, for example, by changing the group 13 nitride crystal particles to mixed crystal particles composed of a plurality of group 13 elements. it can. The band gap refers to a value calculated by converting the peak wavelength of the emission spectrum emitted from the phosphor using the crystal particles into energy.

  In the phosphor of the present invention, the particle size of the group 13 nitride crystal particles is preferably in the range of 0.1 nm to 10 μm, particularly preferably in the range of 0.5 nm to 1 μm, and further preferably in the range of 1 to 20 nm. . This is because when the group 13 nitride crystal particles have a particle size of less than 0.1 nm, the band gap tends to be larger than the energy corresponding to visible light emission, and control tends to be difficult. This is because if the particle size of the crystal particles exceeds 10 μm, light scattering on the surface of the phosphor increases, and characteristics such as light emission efficiency tend to deteriorate. Further, in the phosphor of the present invention, the group 13 nitride crystal particles have an optical band gap that is widened due to the quantum size effect when the particle size is twice or less the Bohr radius, but even in that case, the group 13 nitride crystal particles are in the above band gap range. It is preferable. Of course, the above two control means may be used together for adjustment.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated in detail, this invention is not limited to these.

<Example 1>
Glyoxal (54 g) and cyclohexylamine (81 g) were dissolved in 200 ml of methanol and kept at 0 ° C. for 24 hours to obtain a precursor N, N′-dicyclohexylethylenediimine according to the reaction scheme shown below.

  5.6 g of the obtained precursor and 9 g of gallium trichloride were dissolved in 150 ml of dichloromethane, and a carbene-like structure complex was obtained according to the reaction scheme shown below.

  The obtained carbene-like structure complex was dissolved in 300 ml of benzene and subjected to a heat treatment using an autoclave at a temperature of 430 ° C. and a pressure of 24.2 MPa for 13 hours. Crystals of the particles obtained by filtering and washing the reaction product were evaluated. As a result, X-ray diffraction patterns confirmed that the particles were hexagonal gallium nitride (h-GaN).

<Example 2>
Crystal particles were obtained in the same manner as in Example 1 except that 0.5 ml of ammonia was added in the crystal particle forming step.

  The light emission characteristics of the crystal particles of Examples 1 and 2 were evaluated by measuring the photoluminescence spectrum using a KrF excimer laser with a peak wavelength of 248 nm as excitation light, and both emitted light of gallium nitride having a peak at 365 nm at room temperature. Although the characteristics were confirmed, the emission intensity of the crystal particles obtained in Example 2 was 10 times that of the crystal particles obtained in Example 1.

<Example 3>
After mixing 145 g of glyoxal and 146 g of tertiary butylamine, the mixture was reacted for 24 hours while maintaining at 0 ° C., and N, N′-tertiarybutylethylenediimine as a precursor was obtained according to the reaction scheme shown below.

  4.3 g of the obtained precursor and 9 g of gallium trichloride were dissolved in 150 ml of dichloromethane, and a carbene-like structure complex was obtained by the reaction scheme shown below.

  The obtained carbene-like structure complex was dissolved in 300 ml of benzene and reacted at a temperature of 430 ° C. and a pressure of 24.2 MPa for 13 hours using an autoclave. When the crystal of the powder obtained by filtering and washing the reaction product was evaluated, it was confirmed from the X-ray diffraction pattern that it was hexagonal gallium nitride (h-GaN).

<Example 4>
Crystal particles were obtained in the same manner as in Example 3 except that 3.6 g of urea was added in the crystal particle forming step.

  As described above, the emission characteristics of the crystal particles of Examples 3 and 4 were evaluated. As a result, the emission characteristics of gallium nitride having a peak at 365 nm were confirmed at room temperature. The emission intensity of was 5 times that of the crystal particles obtained in Example 3.

<Example 5>
An ethanol solution of 75.6 g of glyoxal and 200 g of (2,6) diisopropylaniline was mixed in formic acid and reacted for 24 hours, and the precursor 3- (bis (2,6-) was reacted according to the reaction scheme shown below. Diisopropylphenyl) diazobutadiene) was obtained.

  9.63 g of the obtained precursor and 9 g of gallium trichloride were dissolved in 150 ml of dichloromethane, and a carbene-like structure complex was obtained according to the reaction scheme shown below.

  The obtained carbene-like structure complex was dissolved in 300 ml of benzene and reacted at a temperature of 430 ° C. and a pressure of 24.2 MPa for 13 hours using an autoclave. When the crystal of the powder obtained by filtering and washing the reaction product was evaluated, it was confirmed from the X-ray diffraction pattern that it was hexagonal gallium nitride (h-GaN).

<Example 6>
Crystal particles were obtained in the same manner as in Example 5 except that 2 g of hydrazine was added in the crystal particle forming step.

  As described above, the emission characteristics of the crystal particles of Examples 5 and 6 were evaluated. As a result, the emission characteristics of gallium nitride having a peak at 365 nm were confirmed at room temperature. The emission intensity of was 5 times that of the crystal particles obtained in Example 5.

<Example 7>
9.63 g of the precursor obtained in Example 5 and 9.63 g of indium trichloride were dissolved in 150 ml of dichloromethane, and a carbene-like structure complex was obtained according to the following reaction scheme.

  The obtained carbene-like structure complex was dissolved in 300 ml of benzene and reacted at a temperature of 300 ° C. under normal pressure for 13 hours. When the powder obtained by filtering and washing the reaction product was crystallized, it was confirmed to be indium nitride InN from the X-ray diffraction pattern.

<Example 8>
9.63 g of the precursor obtained in Example 5, 9 g of gallium trichloride and 3 g of indium trichloride were dissolved in 200 ml of dichloromethane to obtain a carbene-like structure complex, and then dissolved in 300 ml of benzene, and the temperature was set to 300 using an autoclave. The reaction was carried out at 10 ° C. and a pressure of 10 MPa for 13 hours. When the crystal of the powder obtained by filtering and washing the reaction product was evaluated, it was confirmed by an X-ray diffraction pattern that it was a mixed crystal of gallium nitride and indium nitride (InGaN).

<Example 9>
Metallic gallium and iodine were reacted in benzene at a temperature of 50 ° C. for 12 hours to produce a benzene solution of gallium iodide (GaI). 9.63 g of the precursor obtained in Example 5 was mixed with the benzene solution of gallium iodine described above to obtain a carbene-like structure complex, and then reacted for 13 hours at a temperature of 300 ° C. and a pressure of 10 MPa using an autoclave. When the powder obtained by filtering and washing the reaction product was crystallized, it was confirmed by X-ray diffraction pattern that it was gallium nitride and GaN. When the same synthesis was performed at a temperature of 400 ° C. and a pressure of 20 MPa, the inner wall of the autoclave was corroded and GaN was not generated.

<Example 10>
In the same manner as in Example 9, metal indium and iodine were reacted to prepare a benzene solution of indium iodide (InI). 9.63 g of the precursor obtained in Example 5 was mixed with Example 9, benzene solution of gallium iodide and the above-described benzene solution of indium iodide to obtain a carbene-like structure complex, and then the temperature was measured using an autoclave. The reaction was carried out at 300 ° C. and a pressure of 10 MPa for 13 hours. When the crystal of the powder obtained by filtering and washing the reaction product was evaluated, it was confirmed from the X-ray diffraction pattern that it was a mixed crystal of gallium nitride and indium nitride (InGaN).

<Example 11>
By changing the mixing ratio of indium iodide and gallium iodide and changing the type of the organic compound having an amino group in the same manner as in Example 10, three types of group 13 nitride nanoparticle phosphors were produced. .

  First, InI was obtained in the same manner as in Example 7, and the particle diameter was confirmed by observation with an electron microscope. When this phosphor was irradiated with excitation light, it emitted red light of 650 nm.

Next, the precursor in Example 1 was reacted with gallium trichloride and indium trichloride in the same manner as in Example 8 to obtain a carbene-like structure complex, followed by heat treatment to obtain InGaN nanoparticle crystals. As a result of structural analysis and electron microscope observation, the mixed crystal ratio was In _0.3 Ga _0.7 N and the particle diameter was 10 nm. When this phosphor was irradiated with excitation light, it emitted green light of 550 nm.

Next, after the precursor in Example 5 was reacted with gallium iodide and indium iodide in the same manner as in Example 10 to obtain a carbene-like structure complex, heat treatment was performed to obtain InGaN nanoparticle crystals. As a result of composition analysis and electron microscope observation, the mixed crystal ratio was In _0.2 Ga _0.8 N and the particle size was 8 nm. When this phosphor was irradiated with excitation light, it emitted blue light of 480 nm.

  When the red, green and blue phosphors were mixed in an epoxy resin at a predetermined ratio and irradiated with excitation light after the resin was cured, white light emission was obtained.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

Claims (13)

Reacting an organic compound having an amino group with a dialdehyde to obtain a precursor;
Reacting the precursor with a group 13 element halide to obtain a carbene-like structure complex;
And a step of obtaining a group 13 nitride crystal particle by heat-treating the carbene-like structure complex.   The method of claim 1, wherein the dialdehyde is glyoxal.   The method according to claim 1, wherein the organic compound having an amino group is an aliphatic cyclic hydrocarbon having an amino group.   The method according to claim 3, wherein the organic compound having an amino group is cyclohexylamine.   The method according to claim 1, wherein the organic compound having an amino group is an aliphatic chain hydrocarbon having 4 or more carbon atoms having an amino group.   6. The method according to claim 5, wherein the organic compound having an amino group is tertiary butylamine.   The method according to claim 1, wherein the organic compound having an amino group is an aromatic hydrocarbon having an amino group.   The method according to claim 7, wherein the organic compound having an amino group is 2,6-diisopropylaniline.   The method according to claim 1, wherein the heat treatment is performed by adding at least one of ammonia, urea, and hydrazine.   The method according to claim 1, wherein the group 13 element halide is a group 13 element iodide, and the heat treatment is performed at 400 ° C or lower. A crystal particle comprising a bond of a group 13 element and nitrogen,
A group 13 nitride characterized in that at least one of an aliphatic cyclic hydrocarbon group, an aliphatic chain hydrocarbon group having 4 or more carbon atoms, and an aromatic hydrocarbon group is chemically bonded to the nitrogen as a modifying molecule Crystal particles.   The group 13 nitride crystal particle according to claim 11, wherein the modifying molecule contains at least one of a cyclohexyl group, a tertiary butyl group, and a 2,6-diisopropylphenyl group.   A phosphor using the group 13 nitride crystal particle according to claim 11.