JP2004307679A - Group 13 nitride semiconductor nanoparticle fluorescence material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a group 13 nitride semiconductor nanoparticle fluorescence material which has highly sensitive, uniform luminous characteristics, is safe and has little effect on the environment. <P>SOLUTION: The group 13 nitride semiconductor nanoparticle fluorescence material comprises a group 13 nitride semiconductor nanoparticle and a surface-modifying molecule bonded to the surface of the semiconductor nanoparticle. The group 13 nitride semiconductor nanoparticle is prepared by mixing an organometallic compound containing a group 13 element and a nitrogen raw material and reacting the mixture in a gas phase or in plasma. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

（注） ＴＥＩ：トリエチルインジウム、設定値▲１▼：アンモニア用マスフローコントローラ設定値、設定値▲２▼：窒素用マスフローコントローラ（１）設定値、設定値▲３▼：窒素用マスフローコントローラ（２）設定値
【００６２】
【表２】

（２） 窒化インジウムナノ粒子蛍光材料の作製
得られた窒化インジウムナノ粒子２０ ｍｇを１０−カルボキシデシルジスルフィドの０．３％トルエン溶液２０ ｍｌ中に添加し分散した。限外ろ過により過剰の１０−カルボキシデシルジスルフィドを除去した。窒化インジウムナノ粒子分散液は紫外線ランプの照射により赤色発光した。また、銅メッシュの上にカーボン膜を形成しこの上に上記分散液を滴下し乾燥させてＴＥＭで観察したところ、粒子間に一定の間隔があることを認めた。また、ＦＴ−ＩＲにより粒子上の１０−カルボキシデシルジスルフィドの存在を確認した。
【００６３】
実施例２〜５
（１） 窒化インジウムナノ粒子の作製
表１に示す条件を用いた以外、実施例１と同様の条件で窒化インジウムナノ粒子を製造した。実施例１と同様にして粒子の化学組成及び粒径を測定し、不純物量を評価した。結果を表２に示す。また、電子線回折像により、実施例２〜５のいずれの粒子も実施例１の粒子と同様に窒化インジウムのパターンと一致する回折パターンを示した。
【００６４】
（２） 窒化インジウムナノ粒子蛍光材料
実施例１と同様の方法で１３族窒化物半導体ナノ粒子蛍光材料を製造した。得られた蛍光材料は実施例１と同様に良好な蛍光発色を示し、粒径が小さいほど短波長化した。
【００６５】
実施例６〜 １０
（１） 窒化インジウム／窒化ガリウム（コア／シェル型）ナノ粒子の作製
図２に示す製造装置を用い、窒化インジウム／窒化ガリウム（コア／シェル型）ナノ粒子を作製した。図２に示す装置は１３族の流路を１系統及びリアクタ１０にシェル部生成反応用ヒータ３６及び予熱用ヒータ（図示せず）を１段増やした以外、図１に示す装置と同じである。増設したヒータ３６の直前でＧａ原料であるトリメチルガリウムを導入し、実施例１〜５の窒化インジウムナノ粒子からなるコアの上に窒化ガリウムを被覆してコア／シェル型の窒化インジウム／窒化ガリウムナノ粒子を得た。シェル部（窒化ガリウム）の合成条件は、バブラー３５の温度：１０℃、設定値▲１▼（アンモニア用マスフローコントローラ３の設定値）：２ＳＬＭ、設定値▲２▼（窒素用マスフローコントローラ（４）３２の設定値）：２ＳＬＭ、設定値▲３▼（窒素用マスフローコントローラ（５）３３の設定値）：２ＳＣＣＭ、予熱温度５００℃、反応温度：１０００℃とした。コア部（窒化インジウム）の合成は設定値▲１▼を上記の条件とした以外、実施例１と同様の条件で行った。生成した粒子の回収は、各部の温度が安定するのを待ち、粒子捕集部１１にＰＴＦＥ製のフィルターをセットして行った。
【００６６】
捕集した粒子について化学組成及び粒径を測定したところ、シェル部はＧａ／Ｎ元素比が０．９８で粒径は表２の各実施例の数平均径よりも２〜３ ｎｍ増大していた。
【００６７】
ＴＥＭを用いて電子線回折像をとったところ、回折パターンは上記窒化インジウムのパターンに加えて窒化ガリウムのパターンを示した。
【００６８】
さらに、実施例１と同様にしてオージェ電子分光法により不純物の量を定量し、実施例１と同じ基準で評価した結果◎であることがわかった。
【００６９】
（２） 窒化インジウム／窒化ガリウム（コア／シェル型）ナノ粒子蛍光材料の作製実施例１と同様の方法で１３族窒化物半導体ナノ粒子蛍光材料を製造した。得られた蛍光材料は実施例１〜５の蛍光材料と比較してそれぞれ少し短波化したが蛍光強度は増大した。
【００７０】
実施例 １１
（１）窒化インジウムガリウム／窒化ガリウム（コア／シェル型）ナノ粒子の作製
図４に示す装置を用い、以下の操作により窒化インジウムガリウム／窒化ガリウムのコア／シェル型ナノ粒子を作製した。図４に示す装置は、１３族ナノ粒子の混晶を作製するためのマスフローコントローラ（３）３１、ライン３８、バブラー３４、及びライン３９を追加した以外、図２に示す装置と同じである。まずバブラー６にトリエチルインジウムを入れ、温度を６７．８℃に設定した。バブラー３４にはトリメチルガリウムを入れ、温度を１０℃に設定した。バブラー３５にはトリメチルガリウムを入れ、温度を１０℃に設定した。マスフローコントローラ３の設定値を２ＳＬＭ、マスフローコントローラ（１）４の設定値を１ＳＬＭ、マスフローコントローラ（４）３２の設定値を０．５ＳＬＭにセットした。また、マスフローコントローラ（２）５の設定値を１６ＳＣＣＭ、マスフローコントローラ（３）３１の設定値を０．４ＳＣＣＭ、マスフローコントローラ（５）３３の設定値を２ＳＣＣＭにセットした。マスフローコントローラ（２）５からの窒素をバブラー６、マスフローコントローラ（３）３１からの窒素をバブラー３４、マスフローコントローラ（５）３３からの窒素をバブラー３５に供給し、それぞれ順にトリエチルインジウム、トリメチルガリウム及びトリメチルガリウムの蒸気を発生させた。発生した前者２つの１３族原料の蒸気はマスフローコントローラ（１）４からの窒素と混合し、ライン２４を通して反応管９に送給した。一方、後者のトリメチルガリウム蒸気は、マスフローコントローラ（４）３２からの窒素と混合し、ライン３７を通して反応管９に送給した。ライン２４の１３族原料を含むガスとライン２３のアンモニアガスをリアクタ１０の予熱用ヒータ７により２００℃に予熱した後、リアクタの混合部で乱流を発生させて混合し、石英製円管からなる反応管９に導入した。反応用ヒータ８により反応温度が８００℃になるように反応管９を加熱した。ここまでの工程で粒子のコア部分を形成した。その直後にトリメチルガリウム蒸気を含むライン３７のガスを反応管９に導入し、反応ガスを混合した。さらにシェル部生成反応用ヒータ３６によって９００℃になるように反応管９を加熱した。この工程によって粒子のシェル部分を形成した。その後、反応管９の上部に窒素用流量調節弁１２からの窒素ガスを導入し生成した粒子を含む反応ガスを急冷した。生成した粒子の回収は、各部の温度が安定するのを待ち、粒子捕集部１１にＰＴＦＥ製のフィルターをセットして行った。
【００７１】
捕集した粒子について粒径を測定したところ１３ ｎｍであり、変動係数は２２％であった。また、不純物の評価も◎であった。
【００７２】
（２） 窒化インジウムガリウム／窒化ガリウム（コア／シェル型）ナノ粒子蛍光材料の作製
実施例１と同様の方法で１３族窒化物半導体ナノ粒子蛍光材料を製造した。得られた蛍光材料は橙色のＰＬ発光を示した。
【発明の効果】
上記の通り、本発明の１３族窒化物半導体ナノ粒子発光体は、半導体ナノ粒子の純度が高く粒径分布が狭いため、均一な発光特性を有する。また、１３族窒化物半導体ナノ粒子は比較的安全な化合物であるため人体及び環境に対する影響がすくない。そのため、蛍光標識材料及び発光デバイスの材料として好適である。
【図面の簡単な説明】
【図１】１３族窒化物半導体ナノ粒子を製造する装置の一例を示す構成図である。
【図２】コア／シェル型１３族窒化物半導体ナノ粒子を製造する装置の一例を示す構成図である。
【図３】マイクロ波加熱装置を用いた１３族窒化物半導体ナノ粒子を製造する装置の一例を示す部分構成図である。
【図４】コア／シェル型１３族窒化物半導体ナノ粒子を製造する装置の別の例を示す構成図である。
【図５】本発明の１３族窒化物半導体ナノ粒子蛍光材料の一例を示す概略断面図である。
【図６】本発明の１３族窒化物半導体ナノ粒子蛍光材料の別の例を示す概略断面図である。
【符号の説明】
１・・・アンモニアガスボンベ
２・・・窒素ガスボンベ
３・・・アンモニア用マスフローコントローラ
４・・・窒素用マスフローコントローラ（１）
５・・・窒素用マスフローコントローラ（２）
３１・・・窒素用マスフローコントローラ（３）
３２・・・窒素用マスフローコントローラ（４）
３３・・・窒素用マスフローコントローラ（５）
６，３４，３５・・・バブラー
７・・・予熱用ヒータ
８・・・反応用ヒータ
３６・・・シェル部生成反応用ヒータ
９・・・反応管
１０・・・リアクタ
１１・・・粒子捕集部
１２・・・窒素用流量調節弁
１３・・・マイクロ波加熱装置
１４・・・排ガス処理部
１０１・・・１３族窒化物半導体ナノ粒子
１０２・・・外殻層
１０３・・・表面修飾分子
Ｘ・・・結合性基
Ｙ・・・官能基[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a semiconductor nanoparticle fluorescent material that can be applied to a fluorescent labeling material and a light emitting device.
[0002]
[Prior art]
Nano-sized particulate materials are known to exhibit different properties than bulk materials. For example, in the case of a semiconductor, a so-called quantum size effect in which the band gap, which has been considered to be inherent to conventional materials, changes depending on the size of the particles is well known. The particle size at which this effect becomes significant varies depending on the type of semiconductor material, and is generally several tens of nanometers to several nanometers. For this reason, single nanoparticles are particularly important. In addition, there are materials that are known to have such an effect that the quantum size effect becomes noticeable, and at the same time, the lifetime of fluorescence is shortened, and light emission that has not been observed can be observed. As described above, nano-sized materials, particularly single nano-sized materials, have different characteristics from conventionally known bulk materials, and thus are attracting a great deal of scientific and engineering attention.
[0003]
As the crystallite size of semiconductor nanoparticles decreases due to the quantum size effect, the fluorescence spectrum shifts to the short wavelength side. That is, if nanoparticles having different crystallite sizes are synthesized, various emission spectra can be obtained by excitation with light of a single wavelength. For example, a target molecule is detected by using a semiconductor nanoparticle such as CdSe / CdS (core / shell), CdSe / ZnS (core / shell), and binding a molecular probe to the surface of a bead made of these semiconductor nanoparticles. Semiconductor nanoparticle fluorescent materials have been proposed (see, for example, Non-Patent Documents 1 and 2). These semiconductor nanoparticles can obtain light emission at different wavelengths by using different crystallite sizes. Simultaneous multiplex measurement is also possible by coding a labeled bead with a combination of emission wavelength and emission intensity. The semiconductor nanoparticle fluorescent material has excellent characteristics as a labeling material such as high sensitivity, low cost, and easy automation. Therefore, by using a semiconductor nanoparticle fluorescent material as a labeling material, it is possible to detect a specific site in a living body, a substance in plasma, and the like with high sensitivity and at high speed.
[0004]
Semiconductor nanoparticle fluorescent materials that have improved affinity with a matrix by coating the surface of semiconductor nanoparticles with a modifying molecule have been proposed (see, for example, Patent Documents 1 to 3 and Non-Patent Document 3). By coating the semiconductor nanoparticles with a modifying molecule, it becomes possible to improve the affinity with an aqueous medium or to improve the dispersibility in an organic polymer or an organic solvent. This makes it easy to apply the semiconductor nanoparticle fluorescent material as a labeling material, and to disperse it in a resin to form a light emitting material. As described above, semiconductor nanoparticle fluorescent materials are expected to be widely applied in the fields of optical devices, clinical diagnosis, biochemical / medical research, and the like.
[0005]
When semiconductor nanoparticles are used as a light emitting material, it is important that the emission spectrum has a sharp peak as well as high sensitivity. In particular, when a plurality of nanoparticles having different emission wavelengths are used as the labeling material, the peak width is required to be narrow in order to prevent the emission peaks from overlapping each other. Since the emission wavelength changes with the crystallite size due to the quantum size effect, the crystallite size of the semiconductor nanoparticles must be uniform (narrow particle size distribution) to obtain an emission spectrum with a narrow peak width. is there. However, a technique for producing uniform semiconductor nanoparticles having a crystallite size of several tens to several nanometers has not been sufficiently studied. For example, Cd (CH₃)₂, TOPSe (trioctylphosphine selenide) and TOP (trioctylphosphine) mixed solution is added to TOPO (trioctylphosphine oxide), and a method of growing CdSe crystals is disclosed (Patent Document 1). However, when manufacturing in a liquid phase in this way, there exists a problem that a solvent component decomposes | disassembles and the contamination in a nanoparticle arises.
[0006]
Purity is extremely important for nanoparticles such as luminescent materials. This means that after the particle is excited in some way (light, electron beam, electric field, etc.), it returns to the ground state through the radiation process or returns to the ground state through the non-radiation process, ie does not emit light. This is because it is extremely sensitive to the concentration of impurities. Semiconductor nanoparticles with higher purity usually shine better. Of course, there are exceptions, but even in that case, it is very important that high-purity nanoparticles can be produced because the impurities need to be introduced at a target concentration.
[0007]
Conventionally, CdSe or CdSe / ZnS (core / shell) has been generally used as a semiconductor nanoparticle fluorescent material. However, the use of these materials is problematic from a safety and environmental standpoint. Therefore, since semiconductor nanoparticle fluorescent materials will be widely used in the future, it is desired to replace them with materials that are safer and have less environmental impact.
[0008]
[Patent Document 1]
US Pat. No. 6,319,426
[Patent Document 2]
JP 2002-38145 A
[Patent Document 3]
JP 2003-64278 A
[Non-Patent Document 1]
“Science”, 1998, Vol. 281, No. 25, p. 2013-2016
[Non-Patent Document 2]
“Nature Biotechnology”, 2001, Vol. 19, p. 631-6354
[Non-Patent Document 3]
“Science”, 1998, Vol. 281, No. 25, p. 2016-2018
[0009]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a group 13 nitride semiconductor nanoparticle fluorescent material that has high sensitivity and uniform light emission characteristics, and is safe and has little influence on the environment.
[0010]
[Means for Solving the Problems]
As a result of diligent research in view of the above object, the present inventors have mixed the organometallic compound containing a group 13 element and a nitrogen source (nitrogen raw material) and reacted them in the gas phase or plasma, whereby the particle size distribution is reduced. Narrow, fine and highly pure group 13 nitride semiconductor nanoparticles can be obtained, and by using such group 13 nitride semiconductor nanoparticles, a semiconductor nanoparticle fluorescent material having high sensitivity and uniform emission characteristics can be obtained. The present invention has been discovered.
[0011]
That is, the group 13 nitride semiconductor nanoparticles of the present invention were achieved by the following means.
(1) A group 13 nitride semiconductor nanoparticle fluorescent material having a group 13 nitride semiconductor nanoparticle and a surface modifying molecule bonded to the surface of the semiconductor nanoparticle, wherein the group 13 nitride semiconductor nanoparticle is 13 A group 13 nitride semiconductor nanoparticle fluorescent material obtained by mixing an organic metal compound containing a group element and a nitrogen raw material and reacting them in a gas phase or plasma.
(2) A group 13 nitride semiconductor nanoparticle (core), an outer shell layer (shell) coated with the group 13 nitride semiconductor nanoparticle, and a surface modifying molecule bonded to the surface of the outer shell layer The group 13 nitride semiconductor nanoparticle fluorescent material, wherein the group 13 nitride semiconductor nanoparticle is prepared by mixing an organometallic compound containing a group 13 element and a nitrogen raw material and reacting in a gas phase or plasma. A group 13 nitride semiconductor nanoparticle fluorescent material characterized.
(3) The group 13 nitride semiconductor nanoparticle fluorescent material according to (1) or (2), wherein a particle size distribution of the group 13 nitride semiconductor nanoparticle is a coefficient of variation of 50% or less.
(4) The group 13 nitride semiconductor nanoparticles are substantially composed of a group 13 element and nitrogen, and the ratio of the number of atoms of the group 13 element to nitrogen (group 13 element: nitrogen) is 1: 0.95 to 1: It is 1.05, The group 13 nitride semiconductor nanoparticle fluorescent material in any one of (1)-(3) characterized by the above-mentioned.
(5) The amount of oxygen and carbon contained in the group 13 nitride semiconductor nanoparticles is 0.05 or less in terms of the ratio of the number of atoms with nitrogen. (1) to (4) The group 13 nitride semiconductor nanoparticle fluorescent material according to any one of the above.
(6) The group 13 nitride semiconductor nanoparticles include a core group 13 nitride having a band gap energy of 1.5 to 3.1 eV and a shell portion having a band gap energy exceeding 3.1 eV. It is a core / shell type made of a group 13 nitride, and the core part and the shell part of the group 13 nitride semiconductor nanoparticles are prepared by mixing an organometallic compound containing a group 13 element and a nitrogen raw material in a gas phase or The group 13 nitride semiconductor nanoparticle fluorescent material according to any one of (1) to (5), which is reacted in plasma.
(7) The group 13 element of the group 13 nitride semiconductor nanoparticles is at least one selected from the group consisting of Ga, In, and Al, according to any one of (1) to (6), Group 13 nitride semiconductor nanoparticle fluorescent material.
(8) The group 13 element of the core portion of the group 13 nitride semiconductor nanoparticles is selected from the group consisting of In, Ga and In, Al and In, and Al, Ga and In, and the group 13 of the shell portion The group 13 nitride semiconductor nanoparticles according to (6), wherein the element is selected from the group consisting of Ga, Al, Ga and In, Al and In, Ga and Al, and Al, Ga and In Fluorescent material.
(9) In the method for producing a group 13 nitride semiconductor nanoparticle fluorescent material according to any one of (1) to (8), the group 13 nitride semiconductor nanoparticle production reaction is substantially a tube-shaped reaction tube. A method for producing a Group 13 nitride semiconductor nanoparticle fluorescent material, characterized in that:
(10) The group 13 nitride semiconductor nanoparticles are produced by reacting a group 13 raw material having a saturated vapor pressure of 133 Pa or higher at 50 ° C. and a nitrogen source having a saturated vapor pressure of 50 Pa or higher at 50 ° C. The manufacturing method of the group 13 nitride semiconductor nanoparticle fluorescent material as described in (9).
[0012]
DETAILED DESCRIPTION OF THE INVENTION
[1] Group 13 nitride semiconductor nanoparticles
The group 13 nitride semiconductor nanoparticles are nanoparticles composed of a group 13 element and nitrogen, and the group 13 element represents boron, aluminum, gallium, indium, and tantalum. Of these, Group 13 elements preferably used in the present invention are aluminum, gallium and indium. The semiconductor nanoparticles of the present invention may contain unavoidable impurities, but the ratio of group 13 element to nitrogen (group 13 element: nitrogen) is preferably 1: 0.8 to 1: 1 based on the number of atoms. .2, more preferably 1: 0.9 to 1: 1.1, and most preferably 1: 0.95 to 1: 1.05. A group 13 element may be used alone, or a plurality of group 13 elements may be mixed and used as a mixed crystal. The preferred composition of the group 13 element is gallium alone, indium alone, aluminum alone, a mixed crystal of gallium and indium, a mixed crystal of aluminum and indium, a mixed crystal of gallium and aluminum, and a mixed crystal of aluminum, gallium and indium. The mixing ratio of each element in the case of a mixed crystal can be selected as necessary.
[0013]
The group 13 nitride semiconductor nanoparticles have a core group 13 nitride having a band gap energy of 1.5 to 3.1 eV, and more than 3.1 eV (preferably more than 3.1 eV to about 6.5 eV). ) A core / shell type made of a group 13 nitride of a shell portion having band gap energy may be used. In this case, the group 13 element in the core portion is preferably selected from the group consisting of indium alone, gallium and indium, aluminum and indium, and aluminum, gallium and indium, and the group 13 element in the shell portion is gallium alone and aluminum alone. It is preferably selected from the group consisting of gallium and indium, aluminum and indium, gallium and aluminum, and aluminum, gallium and indium.
[0014]
The number average particle diameter of the semiconductor nanoparticles is preferably 0.5 to 100 nm, more preferably 0.5 to 50 nm, still more preferably 0.5 to 20 nm, and most preferably 0.8. 5-10 nm. The particle size distribution of the semiconductor nanoparticles is preferably 0 to 50%, more preferably 0 to 20%, and still more preferably 0 to 10% in terms of coefficient of variation. The coefficient of variation means a value (arithmetic standard deviation × 100 / number average particle size) obtained by dividing the arithmetic standard deviation by the number average particle size and expressing this as a percentage.
[0015]
The semiconductor nanoparticles may be aggregates, in which case they are so-called soft aggregates in which individual particles can be separated, and aggregates obtained by sintering individual particles (for example, aggregates obtained by a laser ablation method or the like). ) Is not included. The number average particle size and particle size distribution of the semiconductor nanoparticles mean the number average particle size and particle size distribution in the primary particles.
[0016]
The group 13 nitride semiconductor used for the semiconductor nanoparticle fluorescent material of the present invention may have a dopant added as necessary. The kind and addition amount of the dopant may be appropriately selected according to the purpose.
[0017]
[2] Method for producing group 13 nitride semiconductor nanoparticles
As a method for producing a group 13 nitride semiconductor nanoparticle, a method of producing a nanoparticle having a monodispersed and narrow particle size distribution from the beginning may be used, or after producing a nanoparticle having a polydispersed or wide distribution. A method of producing nanoparticles having a desired particle size distribution by classification may be used. Classification is not particularly limited, and a known method can be used. Of these methods, it is preferable to use a method of producing nanoparticles that are monodispersed and have a narrow particle size distribution from the beginning.
[0018]
As a method for producing nanoparticles that are monodispersed in a gas phase or plasma and have a narrow particle size distribution, known methods can be appropriately used. Preferable production methods include a thermal CVD method, a plasma CVD method, a photoexcited CVD method, and the like. Among them, particularly preferable methods are a thermal CVD method and a plasma CVD method. Regarding the process in which nucleation occurs from a gas raw material in the gas phase, and subsequently the final particles are obtained through particle growth, agglomeration, fusion, etc., the explanation by Okuyama et al. (J. Soc. Powder Technol., Japan, 2002) 39, p.274-287).
[0019]
(A) Raw material
Examples of the raw material (Group 13 raw material) containing a Group 13 element used for the production of Group 13 nitride nanoparticles include simple substances and compounds of boron, aluminum, gallium, indium or tantalum. Of these, Ga raw materials (gallium and gallium compounds), Al raw materials (aluminum and aluminum compounds) and In raw materials (indium and indium compounds) are preferable. An organic gallium compound or the like can be used as the Ga material, an organic aluminum compound or the like can be used as the Al material, and an organic indium compound or the like can be used as the In material. Of these group 13 materials, a material having a saturated vapor pressure at 50 ° C. of 133 Pa (1 Torr) or higher is preferably used, and a material of 133 Pa (1 Torr) to 101,300 Pa (760 Torr) is more preferably used, and 399 Pa ( It is more preferable to use a raw material of 3 Torr) to 101,300 Pa (760 Torr).
[0020]
Hereinafter, although the raw material which can be preferably used is specifically enumerated, the compound which can be used as a group 13 raw material is not limited to these examples. Preferred examples of the Ga raw material include diethyl acetylacetonate gallium, diethylcyclopentadienyl gallium, diethyl gallium azide, diethyl gallium chloride, diethyl gallium fluoride, diethyl methylcyclopentadienyl gallium, dimethyl acetylacetonate gallium, dimethylcyclohexane. Pentadienylgallium, dimethylgallium bromide, dimethylgallium chloride, dimethylgalliumdimethylamide, dimethylgallium fluoride, ethylgallium dichloride, methylgallium dichloride, t-butylgallium sulfide, triethylgallium (TEG), triethylgalliumdimethylethylamine Adduct, triisobutylgallium, trimethylgallium (TMG), trimethylgallium dimethylethylamine adduct, trimethylgallium trimethyl Amine adducts, tri-n-butylgallium, tri-n-propylgallium, triphenylgallium, tri-t-butylgallium, tris (acetylacetonato) gallium, tris (dipivaloylmethanato) gallium, tris (hexafluoroacetyl) Acetonato) gallium and the like.
[0021]
Preferable examples of the In raw material include trimethylindium (TMI), triethylindium (TEI), trimethylindium dimethylethylamine adduct, triacetylacetonate indium and the like. Preferred examples of the Al raw material include trisacetylacetonate aluminum, trisdipivaloylmethanato aluminum, trishexafluoroacetylacetonate aluminum, triethylaluminum (TEA), triisobutylaluminum, trimethylaluminum (TMA), ethyl dichloride. Examples thereof include aluminum, methylaluminum dichloride, diethylaluminum chloride, dimethylaluminum hydride, dimethylaluminum amide, and dimethylaluminum dimethylethylamine adduct.
[0022]
Among these compounds, a compound having a relatively low vapor pressure (for example, triacetylacetonato indium) requires a relatively high temperature during supply, and thus has a problem that it is difficult to control the supply amount. In addition, since the raw material supplied in a vapor state may be condensed again into a liquid or solid, it is difficult to maintain uniformity in the gas phase, and the purity, composition, and particle size of the generated particles are likely to be distributed. On the other hand, since a compound having a relatively high vapor pressure can supply vapor at a temperature of about −10 ° C. to about 50 ° C., the apparatus becomes simple and easy to control. Further, once vaporized is unlikely to be condensed again, it is more preferable as a raw material for the group 13 nitride semiconductor nanoparticles.
[0023]
More preferable specific examples of the raw material for the group 13 nitride semiconductor nanoparticles include Ga raw materials such as diethyl gallium chloride, dimethyl acetylacetonate gallium, triethyl gallium (TEG), and trimethyl gallium (TMG), and triethyl indium (TEI). Examples include In raw materials and Al raw materials such as trimethylaluminum (TMA) and triethylaluminum (TEA).
[0024]
As a method of supplying these raw materials, a method of heating in an air stream on a boat for heating, a method of supplying by a spray if it is a liquid raw material, a method of supplying while generating a raw material that is easily vaporized in the system, A method such as a method of supplying by bubbling can be used. A general method often used for vacuum deposition or the like may be used as a method of heating in an air stream on a boat for heating. Although this method can be applied to liquid and solid raw materials and is simple, there is a problem that it is difficult to control the raw material supply amount. The method of supplying by spraying is suitable for supplying a relatively large amount of raw material because the liquid raw material can be efficiently supplied. The method of supplying the raw material that is easily vaporized in the system can be stably supplied by generating an unstable volatile compound in the system. For example, gallium trichloride is heated to produce gallium monochloride, gallium oxide is heated to produce gallium suboxide, and metallic gallium is heated in a gas stream containing chlorine gas or hydrogen chloride to gallium monochloride. There is a method of generating.
[0025]
The bubbling method is a method in which a carrier gas is supplied in the form of bubbles into a Group 13 liquid material having a relatively high vapor pressure and the evaporated Group 13 material is used. Since it can be controlled by the pressure and the flow rate of the carrier gas to be bubbled, it can be particularly preferably used.
[0026]
Although various materials can be used as the nitrogen material, it is preferable to use a material having a saturated vapor pressure at 50 ° C. of 133 Pa (1 Torr) or more, and more preferably a material having a temperature of 399 Pa (3 Torr) or more. The saturated vapor pressure at 50 ° C. being 133 Pa (1 Torr) or more means that the saturated vapor pressure at 50 ° C. is 133 Pa or more, or the critical temperature is exceeded at 50 ° C. For example, nitrogen gas has a critical temperature in the vicinity of −147 ° C., and liquid cannot exist at temperatures higher than this, so there is no saturated vapor pressure itself, but such a state exceeding the critical temperature is liquid at 50 ° C. In the present invention, the saturated vapor pressure at 50 ° C. is defined to be 133 Pa or higher. The same applies to the saturation vapor pressure values of other nitrogen raw materials.
[0027]
Preferred examples of the nitrogen raw material include nitrogen, ammonia, hydrazine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylmethylamine, diethylmethylamine, ethyldimethylamine, propylamine, dipropylamine, and tripropylamine. Butylamine, dibutylamine, tributylamine, nitrous oxide, nitric oxide and the like. More preferable examples include nitrogen, ammonia, hydrazine, methylamine, ethylamine, dimethylamine, trimethylamine, diethylamine, triethylamine and the like. Among them, ammonia can be particularly preferably used because it does not contain carbon that can cause contamination, is a gas at room temperature, and has high reactivity.
[0028]
In order to produce the particles by stably supplying and reacting the above group 13 raw material and nitrogen raw material, it is preferable to use a gas for diluting the raw material and carrying it to the reaction part, that is, a carrier gas, particularly in the gas phase reaction. . Preferable examples of the carrier gas include hydrogen, helium, nitrogen, oxygen, neon, argon and the like. Of these, helium, nitrogen, neon and argon are more preferable.
[0029]
The mixing ratio of the group 13 material to the nitrogen material (nitrogen material / group 13 material) is preferably 100 to 20000, more preferably 300 to 5000 in terms of molar ratio. When the mixing ratio is higher than 20000, the yield decreases, and when it is lower than 100, the purity of the unreacted group 13 raw material or the semiconductor nanoparticles generated by the group 13 element generated by decomposition of the group 13 raw material decreases.
[0030]
(B) Manufacturing equipment
FIG. 1 is a block diagram showing an example of an apparatus used in the method for producing a group 13 nitride semiconductor nanoparticle of the present invention. The apparatus includes a cylinder 1 filled with nitrogen source ammonia gas, a cylinder 2 filled with carrier gas nitrogen gas, a bubbler 6 filled with group 13 material, a reactor 10, a particle collection unit 11, and an exhaust gas treatment. Part 14 is provided. A line 21 exiting from the ammonia gas cylinder 1 is connected to the ammonia mass flow controller 3, and a line 22 exiting from the nitrogen gas cylinder 2 is branched to form a nitrogen mass flow controller (1) 4, a nitrogen mass flow controller (2) 5, and The flow control valve 12 for nitrogen is connected. A line 28 exiting from the nitrogen mass flow controller (2) 5 is connected to a bubbler 6. The bubbler 6 supplies nitrogen to the filled group 13 material, and the group 13 material is evaporated by bubbling. The bubbler 6 is provided with a heater (not shown) so that the group 13 material can be heated to a desired temperature. The line 29 exiting from the bubbler 6 is connected to the line 24 exiting from the nitrogen mass flow controller (1) 4 so that the group 13 raw material vapor and nitrogen can be mixed. The line 24 and the line 23 coming out from the ammonia mass flow controller 3 are respectively connected to a mixing section (not shown) provided in the quartz reaction tube 9 of the reactor 10.
[0031]
By adjusting the settings of the ammonia mass flow controller 3, the nitrogen mass flow controller (1) 4, and the nitrogen mass flow controller (2) 5, the amounts and ratios of the group 13 raw material, ammonia and nitrogen introduced into the reactor 10 are adjusted. be able to.
[0032]
When group 13 nitride semiconductor nanoparticles are mixed, another set of nitrogen mass flow controller (3) 31, line 38, bubbler 34, and line 39 (shown in broken lines in FIG. 1) is installed in parallel. It can produce by doing. For example, when the semiconductor nanoparticles are made of a mixed crystal of gallium and indium, one of the bubblers (bubbler 6) is filled with the In raw material, and the other bubbler (bubbler 34) is filled with the Ga raw material. Nitrogen is supplied to each bubbler, and indium vapor generated in the bubbler 6 and gallium vapor generated in the bubbler 34 are supplied to the line 24 through the line 28 and the line 39, respectively, and mixed. The ratio of gallium and indium in the mixed crystal can be adjusted to a desired ratio by the flow rate of nitrogen gas supplied to each bubbler, the temperature of the bubbler, and the like.
[0033]
FIG. 2 shows an example of an apparatus for producing core / shell group 13 nitride semiconductor nanoparticles. When manufacturing core / shell type nanoparticles, the above-described apparatus shown in FIG. 1 is used for manufacturing the group 13 nitride semiconductor nanoparticles of the core portion, and for manufacturing the group 13 nitride semiconductor nanoparticles of the shell portion. Further, a nitrogen mass flow controller (4) 32, a nitrogen mass flow controller (5) 33, lines 40 and 41, a bubbler 35, a line 37, and a shell portion generation reaction heater 36 are added. As shown in FIG. 2, by introducing the raw material gas of the shell portion immediately before the added heater 36, the core portion particles are coated with the raw material of the shell portion to produce core / shell type nanoparticles. Can do.
[0034]
The reaction tube 9 can be of various known shapes. Particularly preferred is a tubular reaction tube or a reaction tube having a combination of circular tubes. The diameter and length of the reaction tube 9 can be arbitrarily selected depending on the amount of particles to be produced, the amount of gas to be flowed, and the like. Particularly important is the time during which the gas stays in the reaction tube 9. For this reason, it is desirable to determine the diameter and length of the reaction tube 9 from the amount of particles to be produced, the amount of raw material gas to flow, the amount of carrier gas, and the preferred residence time. The residence time of the reaction gas in the reaction tube 9 is preferably 10 milliseconds to 10 seconds, and more preferably 10 milliseconds to 1 second. When the time is shorter than 10 milliseconds, the reaction does not proceed sufficiently, and when the time is longer than 10 seconds, the generated particles grow and the particle size distribution becomes wide.
[0035]
The reactor 10 preferably has a configuration including a preheating part, a mixing part, and a reaction part. A preheating part is a part which heats beforehand in the state which a 13th group raw material and a nitrogen raw material do not mix, By this, it can be made to react rapidly at the time of mixing. A preheating heater 7 is provided in the preheating portion, and the group 13 raw material and the nitrogen raw material can be heated to a predetermined temperature in advance. The shape of the preheating portion can be any shape, but is preferably a simple circular tube. The mixing part is a part for mixing the group 13 raw material and the nitrogen raw material, and in order to produce a group 13 nitride semiconductor nanoparticle having a high purity and being monodispersed and having a narrow particle size distribution. is important. This part is preferably designed so as to cause turbulence by constriction or by narrowing one of the two raw material outlets to be mixed.
[0036]
The reaction part is a part that is continuous with the mixing part, and is a part where the mixed gas causes a chemical reaction to generate group 13 nitride semiconductor nanoparticles. In order to prevent this part from adhering the generated particles to the wall surface, it is preferable that the reaction tube 9 has a relatively simple shape. Specifically, it is preferably a substantially circular tube type, particularly preferably a circular tube type. The circular tube type means that the inner shape of the reaction part has a circular cross section when cut perpendicular to the direction in which the source gas and the carrier gas flow. The circular tube type reaction tube is preferably a simple cylindrical shape without an obstacle inside. The circularity of the circular tube type reaction tube is the radius of the smallest inscribed circle and the largest inscribed circle radius in the inner sectional shape when cut perpendicularly to the flow direction of the source gas and the carrier gas. The ratio to is preferably 1 to 1.4, more preferably 1 to 1.2, and most preferably 1 to 1.1. In addition, the phrase “substantially circular tube type” means that, in addition to the case of a simple circular tube type, changes may be made without departing from the object of the present invention. For example, in order to prevent the generation of particles and precipitates on the wall surface, an infinite number of holes are formed in the inner wall of the circular tube and gas is supplied from these holes, or the sheath gas flows along the inner wall of the circular tube Ingenuity may be given. A reaction heater 8 is provided in the reaction section so that it can be heated to a desired temperature.
[0037]
Various known materials can be used as the material of the reaction tube 9. Since the reaction becomes high temperature, those having high heat resistance are preferred, and specifically, quartz glass, sintered alumina, a high melting point metal or the like is preferably used. In particular, quartz glass can be melted and processed, so that it is possible to produce a reaction tube 9 having a complicated shape, and it is particularly preferable because it is transparent so that the inside can be seen.
[0038]
The reaction temperature is preferably 700 to 1200 ° C, more preferably 850 to 1150 ° C, and particularly preferably 950 to 1150 ° C. It is very important to accurately control the reaction temperature. If the temperature is too low, the raw material will not react sufficiently, so the yield will be low or decomposition of the raw material will be insufficient and impurities will be mixed in, and if the temperature is too high, undesirable side reactions such as decomposition of the generated particles will occur again. Get up. The preheating temperature can be selected from room temperature to the reaction temperature. Preferably it is room temperature-reaction temperature -200 degreeC, More preferably, it is 200 degreeC-reaction temperature -400 degreeC.
[0039]
When producing core / shell group 13 nitride semiconductor nanoparticles, the reaction temperature for forming the core part and the shell part may be the same as the above reaction temperature. Alternatively, the shell raw material may be preheated before being supplied to the reaction tube 9. The preheating temperature may be the same as the preheating temperature. The particle size of the core portion and the thickness of the shell portion covering the core portion can be adjusted to the desired particle size and thickness by appropriately adjusting the amount of source gas supplied, the amount of carrier gas, and the residence time. it can.
[0040]
Various known methods can be used as a method of heating the reactor 10. Specifically, a method of heating by a resistance heating electric furnace, a reflection furnace of a method of irradiating a heat ray, or the like can be preferably used. It is more preferable to use a resistance heating electric furnace because of high temperature stability and uniformity.
[0041]
It is preferable that the end of the reaction part is provided with a mechanism for rapidly cooling the reaction gas containing the generated nanoparticles. By quenching the reaction gas, the end point of the reaction becomes clear, and the generated particles can be prevented from thermal decomposition, aggregation, adhesion to the wall surface, and the like. This increases the yield of recovered particles, increases the purity, and narrows the particle size distribution. As a method for rapidly cooling the reaction gas, a method of mixing with a gas having a low temperature, a method of contacting with a cooled wall surface, or the like can be used. Among them, a method of mixing with a gas having a low temperature is particularly preferable because it can be instantaneously cooled and there is little adhesion of particles to the wall surface. In the example shown in FIGS. 1 and 2, a line 25 from the nitrogen flow control valve 12 is connected to the upper part of the reaction tube 9 to instantaneously cool particles generated by mixing the reaction gas with nitrogen. Can do.
[0042]
The produced particles can be recovered using various known methods. In the example shown in FIG. 1 and FIG. 2, a line 26 coming out from the top of the reaction tube 9 is connected to the particle collecting unit 11, and the generated particles are sent to the particle collecting unit 11 through the line 26. Collected by the collecting unit 11. As a collecting method in the particle collecting unit 11, a method of collecting using a filter, a method of collecting using an electrostatic collector, a method of collecting using a thermophoretic collector, or the like is preferably used. be able to. The collected semiconductor nanoparticles may be further classified as necessary.
[0043]
FIG. 3 is a partial configuration diagram showing another example of a manufacturing apparatus used for manufacturing the group 13 nitride semiconductor nanoparticles of the present invention. The reactor 10 includes a mixing unit and a reaction unit. A line 23 exiting from the ammonia mass flow controller 3 and a line 24 exiting from the nitrogen mass flow controller (1) 4 are connected to a mixing section (not shown) of the reaction tube 9, respectively. A microwave heating device 13 is provided in the reaction tube 9, and a line 25 from the nitrogen flow rate control valve 12 is connected to the upper portion of the reaction tube 9, and a line 26 exiting from the top of the reaction tube 9. Is connected to the particle collecting section 11. The parts other than the reactor 10 are the same as those of the manufacturing apparatus shown in FIG.
[0044]
After mixing ammonia from the line 23 and the group 13 raw material from the line 24 in the mixing section of the reaction tube 9 of the reactor 10, the raw material mixed in the microwave heating device 13 is instantaneously heated through the reaction tube 9. And react in the generated plasma. The generated particles are quenched with nitrogen and then sent to the particle collecting unit 11 for collection. As in the case of the manufacturing apparatus shown in FIG. 1, the shape of the reaction tube 9 is preferably substantially a circular tube type, and is particularly preferably a circular tube type. The time that the gas stays in the reaction tube 9 is preferably 1 to 10 seconds, and more preferably 1 to 100 milliseconds. The reaction temperature is preferably 700 to 1200 ° C, more preferably 850 to 1150 ° C, and particularly preferably 950 to 1150 ° C. The material of the reaction tube 9 is preferably quartz or alumina, particularly quartz. In this example, it is not necessary to preheat the raw material gas in advance, and the raw material gas may be reacted through the reaction tube 9 immediately after mixing the raw materials. When producing core / shell group 13 nitride semiconductor nanoparticles, as in the production apparatus shown in FIG. 2, the number of channels of the group 13 raw material is increased by one system, and the microwave heating device 13 is further increased by one stage. It can manufacture by introducing the raw material for shells just before the expanded microwave heating device 13.
[0045]
[3] Group 13 nitride semiconductor nanoparticle fluorescent material
(A) Outer shell layer
The group 13 nitride semiconductor nanoparticle fluorescent material of the present invention may have an outer shell layer (shell). The semiconductor nanoparticles obtained by the above-described method are coated with a compound having a larger band gap energy, whereby the energy state on the surface of the semiconductor nanoparticles is stabilized and the light emission efficiency is improved. The semiconductor nanoparticle fluorescent material may be a so-called core / shell type semiconductor nanoparticle, or may have a structure in which a plurality of semiconductor nanoparticles are coated with an outer shell layer.
[0046]
The material forming the outer shell layer may be a known material. For example, ZnO, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgS, MgSe, MgTe, GaN, GaP, GaAs, GaSb, HgO, HgS, HgSe, HgTe, InAs, InN, InP, InSb, AlAs, AlN, AlP, AlSb, BN, BaS, SiO₂TiO₂, And two or more kinds of these alloys and mixtures. A material having a band gap larger than the band gap of the group 13 nitride semiconductor nanoparticles as the core is preferable. For example, ZnS, GaN, AlN, MgS, MgSe, MgTe and the like can be mentioned.
[0047]
The outer shell layer is not limited to the case where the semiconductor nanoparticles are completely covered, and may be partially covered. The area ratio is preferably 50% or more with respect to the surface of the semiconductor nanoparticles. A method for forming the outer shell layer is not particularly limited, and a known method may be appropriately used. For example, a hot soap method which is a liquid phase manufacturing method can be used. At that time, since the surface of the group 13 nitride semiconductor nanoparticles is rapidly changed to an oxide in the air, it is preferable to perform the reaction in an inert gas such as nitrogen or argon. In order to remove the trace amount of moisture and oxygen contained in commercially available nitrogen gas and argon gas, or the trace amount of moisture adsorbed on the surface of the container enclosing the inert gas, a desiccant and oxygen scavenger are used together with the inert gas. Use in combination is also preferred.
[0048]
In the present invention, particularly preferred group 13 nitride semiconductor nanoparticles are the core / shell type in which both the core part and the shell part are made of a group 13 nitride as described above, and both the core part and the shell part contain an organic group 13 element. This is a production method in which a metal compound and a nitrogen raw material are mixed and reacted in a gas phase or plasma.
[0049]
(B) Surface modifying molecule
The surface modifying molecule has a matrix affinity region and a binding group that binds to the surface of the group 13 nitride semiconductor nanoparticle or outer shell layer (shell). By bonding the surface modifying molecules, the group 13 nitride semiconductor nanoparticles can be separated from each other. The group 13 nitride semiconductor nanoparticle fluorescent material of the present invention can be used in an organic medium such as an organic solvent or a resin, or can be used in an aqueous medium. The matrix affinity region is appropriately selected according to the medium to be used. For example, when the semiconductor nanoparticle fluorescent material is used in a hydrophobic organic medium, the matrix affinity region is preferably composed of a hydrophobic region mainly composed of aliphatic hydrocarbons and aromatic hydrocarbons. When the semiconductor nanoparticle fluorescent material is used in an aqueous medium, the matrix affinity region is a hydrophilic region containing a carboxyl group, a sulfonic acid group, a phosphoric acid group, a phosphonic acid group, a hydroxyl group, an amino group, an amide group, or a salt thereof. Preferably it consists of.
[0050]
As the binding group bonded to the surface of the group 13 nitride semiconductor nanoparticle or the outer shell layer (shell), known binding groups described in Patent Documents 1 to 3, Non-Patent Document 3, and the like can be used. For example, nitrogen-containing functional groups (amino group, pyridine ring group, nitrile group, etc.), sulfur-containing functional groups (mercapto group, methyl sulfide group, methyl disulfide group, thioacid group, dithioacid group, xanthate group, xanthate group, Isothiocyanate group, thiocarbamate group, thiophene ring, etc.), acidic group (carboxyl group, sulfonic acid group, phosphonic acid group, phosphinic acid group, phosphonic acid partial ester group, phosphinic acid partial ester group, etc.) and their salts, amide groups (Carboxylic acid amide group, sulfonic acid amide group, phosphonic acid amide group, phosphinic acid amide group and the like), phosphine group, phosphine oxide group, hydroxyl group and the like.
[0051]
FIG. 5 is a schematic cross-sectional view showing an example of the group 13 nitride semiconductor nanoparticle fluorescent material of the present invention. The core group 13 nitride semiconductor nanoparticles 101 are covered with an outer shell layer (shell) 102, and surface modifying molecules 103 are bonded to the surface of the outer shell layer 102 by a binding group X. The mode of bonding by the bonding group X is not particularly limited, and may be a coordinate bond or a covalent bond. The surface modification molecule 103 has a matrix affinity region, and the structure of the matrix affinity region can be appropriately selected according to the intended use of the nanoparticle fluorescent material as described above.
[0052]
When the group 13 nitride semiconductor nanoparticle fluorescent material of the present invention is used as a fluorescent labeling material or the like, the surface modifying molecule should bind to nucleic acid (oligonucleotide or the like), antibody, protein, polysaccharide, etc. in addition to the binding group. Amino group, carboxyl group, sulfonic acid group, urea group, -NHCONH₂It is preferable to have a functional group such as Preferred examples of the surface-modifying molecule having these functional groups include mercaptoacetic acid, 2-mercaptoethanesulfonic acid, 2-aminoethanethiol, 2-mercaptopropionic acid, 7-carboxy-1-heptanethiol, 11-mercaptoundecane. Examples include acids, 4,4′-dithiodibutanoic acid, 10-carboxydecyl disulfide, dithiobis (succinimidyl octanoate), dithiobis (succinimidyl undecanoate), and ω-mercapto fatty acid amidoamines. FIG. 6 is a schematic cross-sectional view showing another example of the group 13 nitride semiconductor nanoparticle fluorescent material of the present invention. In this example, the surface modification molecule 103 has a functional group Y together with the binding group X, and can bind to a ligand or the like by the functional group Y.
[0053]
It is confirmed by chemical analysis that the surface of the group 13 nitride semiconductor nanoparticles is covered with a modifying molecule, when observed with a high-resolution TEM such as FE-TEM, and a certain interval between the particles. can do.
[0054]
【Example】
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.
[0055]
Example 1
(1) Preparation of indium nitride nanoparticles
Using the apparatus shown in FIG. 1, indium nitride nanoparticles were produced by the following operation. First, triethylindium was put into the bubbler 6, the mass flow controller 3 was set to 1 SLM, the mass flow controller (1) 4 was set to 1 SLM, and the mass flow controller (2) 5 was set to 10 SCCM. The temperature of the bubbler 6 was set to 80 ° C., and nitrogen from the mass flow controller (2) 5 was supplied to the bubbler 6 to generate triethylindium vapor. The generated triethylindium vapor was mixed with nitrogen from the mass flow controller (1) 4 and sent to the reactor 10 through the line 24. The gas containing triethylindium in the line 24 and the ammonia gas in the line 23 are preheated to 200 ° C. by the heating device 7 of the reactor 10, and then turbulent flow is generated and mixed in the mixing portion of the reactor 10 to form a quartz circular tube. The reaction tube 9 was introduced. The reaction tube 9 was heated by the heating device 8 so that the reaction temperature became 800 ° C., and the reaction gas containing particles generated by introducing nitrogen gas from the nitrogen flow control valve 12 into the upper portion of the reaction tube 9 was rapidly cooled. . The generated particles were collected by waiting for the temperature of each part to stabilize, and setting the PTFE filter in the particle collecting unit 11.
[0056]
In order to analyze the chemical composition of the particles, an electrostatic collector is set in the particle collector 11 under the same conditions as described above, and a TEM grid is fixed to the counter electrode while corona discharge is performed in the gas. Part of the particles was collected on a TEM grid. For particles collected by the filter, indium was analyzed by ICP emission spectrometry (SPS4000, manufactured by Seiko Instruments Inc.), and nitrogen was inert gas melting-thermal conductivity method (EMGA-620W / C, manufactured by Horiba, Ltd.). Quantified with. The results are shown in Table 2.
[0057]
Further, the particles collected on the TEM grid were observed with a TEM (transmission electron microscope), the particle size was measured, and the coefficient of variation was obtained. The shape of the generated particles was not circular but somewhat squared, and the shape projected on the TEM photograph was close to a triangle and was frequently observed. Since it was not circular, the particle diameter was evaluated by using the diameter of the circle when the projected area was considered as the area of the circle, that is, the area equivalent diameter.
[0058]
Furthermore, when the electron diffraction pattern was taken using TEM, it turned out that a diffraction pattern corresponds with the pattern of indium nitride.
[0059]
The amount of impurities was analyzed by Auger electron spectroscopy (device name: SAM-670, manufactured by PHI). The amount of carbon and oxygen impurities was quantified by the standard sensitivity value of the apparatus, and evaluated based on the following criteria. The results are shown in Table 2.
[0060]
Impurity level evaluation criteria
A: The ratio of the number of atoms to nitrogen is less than 0.03 for both oxygen and carbon
○: One is 0.03 or more but both are 0.05 or less
Δ: Both 0.03 or more and 0.05 or less
×: Not applicable to any of these
[0061]
[Table 1]

(Note) TEI: Triethylindium, set value (1): Mass flow controller set value for ammonia, set value (2): Mass flow controller for nitrogen (1) Set value, set value (3): Mass flow controller for nitrogen (2) Setting value
[0062]
[Table 2]

(2) Fabrication of indium nitride nanoparticle fluorescent material
20 mg of the obtained indium nitride nanoparticles were added and dispersed in 20 ml of a 0.3% toluene solution of 10-carboxydecyl disulfide. Excess 10-carboxydecyl disulfide was removed by ultrafiltration. The indium nitride nanoparticle dispersion emitted red light when irradiated with an ultraviolet lamp. Further, when a carbon film was formed on a copper mesh, the dispersion was dropped onto the copper mesh, dried, and observed with a TEM, it was found that there was a certain interval between the particles. The presence of 10-carboxydecyl disulfide on the particles was confirmed by FT-IR.
[0063]
Examples 2-5
(1) Preparation of indium nitride nanoparticles
Indium nitride nanoparticles were produced under the same conditions as in Example 1 except that the conditions shown in Table 1 were used. In the same manner as in Example 1, the chemical composition and particle size of the particles were measured, and the amount of impurities was evaluated. The results are shown in Table 2. Further, from the electron beam diffraction image, all the particles of Examples 2 to 5 showed a diffraction pattern that coincided with the pattern of indium nitride in the same manner as the particles of Example 1.
[0064]
(2) Indium nitride nanoparticle fluorescent material
A group 13 nitride semiconductor nanoparticle fluorescent material was produced in the same manner as in Example 1. The obtained fluorescent material showed good fluorescent color development as in Example 1, and the shorter the particle size, the shorter the wavelength.
[0065]
Example 6- 10
(1) Preparation of indium nitride / gallium nitride (core / shell type) nanoparticles
Indium nitride / gallium nitride (core / shell type) nanoparticles were produced using the production apparatus shown in FIG. The apparatus shown in FIG. 2 is the same as the apparatus shown in FIG. 1 except that one passage is provided for the group 13 channel and the reactor 10 is provided with one additional heater 36 and a preheating heater (not shown). . Trimethyl gallium, which is a Ga raw material, is introduced immediately before the added heater 36, and the core made of the indium nitride nanoparticles of Examples 1 to 5 is coated with gallium nitride to form a core / shell type indium nitride / gallium nitride nano. Particles were obtained. The synthesis condition of the shell part (gallium nitride) is as follows: temperature of the bubbler 35: 10 ° C., set value {circle around (1)} (set value of the mass flow controller 3 for ammonia): 2 SLM, set value {circle around (2)} (mass flow controller for nitrogen (4) 32 set value): 2 SLM, set value {circle around (3)} (set value of nitrogen mass flow controller (5) 33): 2SCCM, preheating temperature 500 ° C., reaction temperature: 1000 ° C. The synthesis of the core part (indium nitride) was performed under the same conditions as in Example 1 except that the set value (1) was set as the above condition. The generated particles were collected by waiting for the temperature of each part to stabilize, and setting the PTFE filter in the particle collecting unit 11.
[0066]
When the chemical composition and particle size of the collected particles were measured, the shell portion had a Ga / N element ratio of 0.98, and the particle size was increased by 2 to 3 nm from the number average diameter of each Example in Table 2. It was.
[0067]
When an electron diffraction pattern was taken using TEM, the diffraction pattern showed a gallium nitride pattern in addition to the indium nitride pattern.
[0068]
Further, the amount of impurities was quantified by Auger electron spectroscopy in the same manner as in Example 1, and it was found that the result was evaluated according to the same criteria as in Example 1.
[0069]
(2) Production of indium nitride / gallium nitride (core / shell type) nanoparticle fluorescent material A group 13 nitride semiconductor nanoparticle fluorescent material was produced in the same manner as in Example 1. The obtained fluorescent materials were a little shorter than the fluorescent materials of Examples 1 to 5, respectively, but the fluorescence intensity increased.
[0070]
Example 11
(1) Preparation of indium gallium nitride / gallium nitride (core / shell type) nanoparticles
Using the apparatus shown in FIG. 4, core / shell nanoparticles of indium gallium nitride / gallium nitride were produced by the following operation. The apparatus shown in FIG. 4 is the same as the apparatus shown in FIG. 2 except that a mass flow controller (3) 31, a line 38, a bubbler 34, and a line 39 for producing a mixed crystal of group 13 nanoparticles are added. First, triethylindium was put into the bubbler 6 and the temperature was set to 67.8 ° C. The bubbler 34 was charged with trimethylgallium and the temperature was set to 10 ° C. The bubbler 35 was charged with trimethylgallium and the temperature was set to 10 ° C. The set value of the mass flow controller 3 was set to 2 SLM, the set value of the mass flow controller (1) 4 was set to 1 SLM, and the set value of the mass flow controller (4) 32 was set to 0.5 SLM. Further, the setting value of the mass flow controller (2) 5 was set to 16 SCCM, the setting value of the mass flow controller (3) 31 was set to 0.4 SCCM, and the setting value of the mass flow controller (5) 33 was set to 2 SCCM. Nitrogen from mass flow controller (2) 5 is supplied to bubbler 6, nitrogen from mass flow controller (3) 31 is supplied to bubbler 34, nitrogen from mass flow controller (5) 33 is supplied to bubbler 35, and triethylindium, trimethylgallium and Trimethylgallium vapor was generated. The generated two group 13 raw material vapors were mixed with nitrogen from the mass flow controller (1) 4 and sent to the reaction tube 9 through the line 24. On the other hand, the latter trimethylgallium vapor was mixed with nitrogen from the mass flow controller (4) 32 and sent to the reaction tube 9 through the line 37. The gas containing the Group 13 raw material in the line 24 and the ammonia gas in the line 23 are preheated to 200 ° C. by the preheating heater 7 of the reactor 10 and then mixed by generating turbulent flow in the mixing section of the reactor. The reaction tube 9 was introduced. The reaction tube 9 was heated by the reaction heater 8 so that the reaction temperature became 800 ° C. The core portion of the particle was formed by the steps so far. Immediately after that, the gas in the line 37 containing trimethylgallium vapor was introduced into the reaction tube 9 and the reaction gas was mixed. Further, the reaction tube 9 was heated to 900 ° C. by the shell portion generation reaction heater 36. This step formed the shell portion of the particles. Thereafter, nitrogen gas from the nitrogen flow rate control valve 12 was introduced into the upper part of the reaction tube 9 to rapidly cool the reaction gas containing the generated particles. The generated particles were collected by waiting for the temperature of each part to stabilize, and setting the PTFE filter in the particle collecting unit 11.
[0071]
The particle diameter of the collected particles was measured and found to be 13 nm, and the coefficient of variation was 22%. The evaluation of impurities was also ◎.
[0072]
(2) Fabrication of indium gallium nitride / gallium nitride (core / shell type) nanoparticle fluorescent material
A group 13 nitride semiconductor nanoparticle fluorescent material was produced in the same manner as in Example 1. The obtained fluorescent material showed orange PL emission.
【The invention's effect】
As described above, the group 13 nitride semiconductor nanoparticle phosphor of the present invention has uniform emission characteristics because the purity of the semiconductor nanoparticles is high and the particle size distribution is narrow. In addition, since the group 13 nitride semiconductor nanoparticles are relatively safe compounds, they do not affect the human body and the environment. Therefore, it is suitable as a fluorescent labeling material and a light emitting device material.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an example of an apparatus for producing a group 13 nitride semiconductor nanoparticle.
FIG. 2 is a configuration diagram showing an example of an apparatus for producing core / shell type group 13 nitride semiconductor nanoparticles.
FIG. 3 is a partial configuration diagram showing an example of an apparatus for producing group 13 nitride semiconductor nanoparticles using a microwave heating apparatus.
FIG. 4 is a block diagram showing another example of an apparatus for producing core / shell type group 13 nitride semiconductor nanoparticles.
FIG. 5 is a schematic cross-sectional view showing an example of a group 13 nitride semiconductor nanoparticle fluorescent material of the present invention.
FIG. 6 is a schematic cross-sectional view showing another example of the group 13 nitride semiconductor nanoparticle fluorescent material of the present invention.
[Explanation of symbols]
1 ... Ammonia gas cylinder
2 ... Nitrogen gas cylinder
3. Mass flow controller for ammonia
4 ... Mass flow controller for nitrogen (1)
5 ... Mass flow controller for nitrogen (2)
31 ... Mass flow controller for nitrogen (3)
32 ... Mass flow controller for nitrogen (4)
33 ... Mass flow controller for nitrogen (5)
6, 34, 35 ... Bubbler
7 ... Preheater heater
8 ... Reaction heater
36... Heater for generating shell part reaction
9 ... Reaction tube
10 ... Reactor
11 ... Particle collection part
12 ... Flow control valve for nitrogen
13 ... Microwave heating device
14 ... Exhaust gas treatment section
101... Group 13 nitride semiconductor nanoparticles
102 ... outer shell layer
103 ... Surface modifying molecule
X: Bonding group
Y ... Functional group

Claims (8)

A group 13 nitride semiconductor nanoparticle fluorescent material having a group 13 nitride semiconductor nanoparticle and a surface modifying molecule bonded to the surface of the semiconductor nanoparticle, wherein the group 13 nitride semiconductor nanoparticle comprises a group 13 element. A group 13 nitride semiconductor nanoparticle fluorescent material obtained by mixing an organometallic compound and a nitrogen raw material and reacting them in a gas phase or plasma. A group 13 having a group 13 nitride semiconductor nanoparticle (core), an outer shell layer (shell) coated with the group 13 nitride semiconductor nanoparticle, and a surface modifying molecule bonded to the surface of the outer shell layer In the nitride semiconductor nanoparticle fluorescent material, the group 13 nitride semiconductor nanoparticle is formed by mixing an organometallic compound containing a group 13 element and a nitrogen raw material and reacting them in a gas phase or plasma. Group 13 nitride semiconductor nanoparticle fluorescent material. The group 13 nitride semiconductor nanoparticle fluorescent material according to claim 1 or 2, wherein the group 13 nitride semiconductor nanoparticle has a particle size distribution with a coefficient of variation of 50% or less. Semiconductor nanoparticle fluorescent material. The group 13 nitride semiconductor nanoparticle fluorescent material according to claim 1, wherein the group 13 nitride semiconductor nanoparticle is substantially composed of a group 13 element and nitrogen, and the group 13 element and nitrogen atoms. A group 13 nitride semiconductor nanoparticle fluorescent material having a ratio of the numbers (group 13 element: nitrogen) of 1: 0.95 to 1: 1.05. The group 13 nitride semiconductor nanoparticle fluorescent material according to any one of claims 1 to 4, wherein the amount of oxygen and carbon contained in the group 13 nitride semiconductor nanoparticle is a ratio of the number of atoms to nitrogen. A group 13 nitride semiconductor nanoparticle fluorescent material characterized by being 0.05 or less. The group 13 nitride semiconductor nanoparticle fluorescent material according to any one of claims 1 to 5, wherein the group 13 nitride semiconductor nanoparticle is a core portion 13 having a band gap energy of 1.5 to 3.1 eV. A core / shell type composed of a group nitride and a group 13 nitride of a shell part having a band gap energy exceeding 3.1 eV, and the core part and the shell part of the group 13 nitride semiconductor nanoparticles are: A group 13 nitride semiconductor nanoparticle fluorescent material obtained by mixing an organometallic compound containing a group 13 element and a nitrogen raw material and reacting in a gas phase or plasma. The group 13 nitride semiconductor nanoparticle fluorescent material according to any one of claims 1 to 6, wherein the group 13 element of the group 13 nitride semiconductor nanoparticle is at least one selected from the group consisting of Ga, In, and Al. A group 13 nitride semiconductor nanoparticle fluorescent material characterized by being. The group 13 nitride semiconductor nanoparticle fluorescent material according to claim 6, wherein the group 13 element of the core portion of the group 13 nitride semiconductor nanoparticle is In, Ga and In, Al and In, and Al and Ga. Selected from the group consisting of In, wherein the group 13 element of the shell part is selected from the group consisting of Ga, Al, Ga and In, Al and In, Ga and Al, and Al, Ga and In Group 13 nitride semiconductor nanoparticle fluorescent material.

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