CN102249199A - Microwave-assisted solvothermal synthesis method of I-III-VI semiconductor material nano-powder - Google Patents

Abstract

The invention discloses a method for microwave-assisted solvothermal synthesis of I-III-VI semiconductor material nanopowder. Put the metal salt and sulfur source or selenium source into the beaker according to the molar ratio of the expected product, add the solvent, mix well and then move it into the microwave reactor; after the reactor is sealed, heat it to the rated temperature in the microwave field and keep it for the rated time; The final product was centrifuged to obtain the target powder. Described solvent is one or more in water, ethylenediamine, ethylene glycol, hydrazine and ethanol; Described metal salt is the metal salt of Cu, In, Ga and Al; Described sulfur source is thiourea or Sulfur powder; the selenium source is selenium powder or selenous acid. The invention is based on the heating and activation of the microwave field, which reduces the reaction temperature and shortens the reaction time; and also enables some reactions that cannot be carried out in the traditional high-pressure solvothermal synthesis to proceed smoothly. The prepared semiconductor material nanopowder has the advantages of small grain size of the product, pure phase, and precise control of the stoichiometric ratio of the phase.

Description

Method for Microwave-Assisted Solvothermal Synthesis of Ⅰ-Ⅲ-Ⅵ Group Semiconductor Materials Nanopowders

technical field

The invention relates to a microwave-assisted solvothermal synthesis method of I-III-VI semiconductor materials. The synthesized semiconductor materials can be used in solar cells, photoelectric sensors and other technical fields, especially widely used in CIS/CIGS thin films Solar cell absorber material.

Background technique

In recent years, the research and development of solar cells has been paid more and more attention, especially the development of thin-film solar cells with direct bandgap materials has become a new research hotspot. Because thin-film solar cells have the characteristics of less consumable materials and high photoelectric conversion, the cost of battery devices is greatly reduced. In the research of thin film solar cells, Cu(In, Ga)Se ₂ , CuInS ₂ , CuInSe ₂ , Cu(In, Ga)(Se, S) ₂ , CuAlSe ₂ , Cu(In, Al)Se ₂ , Cu( In, Ga, Al)Se ₂ and other semiconductor materials have very high light absorption coefficient, and the structure is stable ([1]Karg F H. Development and Manufacturing of CIS, Thin Film Solar Modules.Solar Energy Materials and Solar Cells[J] , 2001, 66: 645-653. [2] J.Olejnícek, CA Kamler, A.Mirasano, et al.A non-vacuum process for preparing nanocrystalline CuIn _1-x Ga _x Se ₂ materials involving an open-air solvothermal reaction, Solar Energy Materials & Solar Cells [J]. 2010(94): 8-11.). It can be used in the development and production of CIGS series thin film solar cells, photoelectric sensors and other fields. Liquid phase synthesis of the above materials, followed by film formation and densification to form a thin film is a very attractive preparation process for the absorbing layer. However, the conditions for the traditional solvothermal synthesis of the above materials are relatively harsh, the reaction temperature is high, the speed is slow, and the required reaction time is long. Usually, the solvothermal synthesis of Cu(In, Ga)Se ₂ , CuInS ₂ , CuInSe ₂ , CuS, CuSe, Ga ₂ Se ₃ , Ga ₂ S ₃ , In ₂ Se ₃ , In ₂ S ₃ needs to be sealed under high pressure. Long-term insulation can only be carried out at a higher temperature in the environment ([3]Y.-G.Chun, K.-H.Kim, K.-H.Yoon.Synthesis of CuInGaSe ₂ nanoparticles by solvothermal route.Thin Solid Films[J ], 2005(480481): 4649. [4] Yu-Hsiang A.Wang, Changqing Pan, Ningzhong Bao et al.Synthesis of ternary and quaternary CuIn _x Ga _1-x Se ₂ (0≤x≤1)semiconductornanocrystals, Solid State Sciences [J]. 2009(11): 1961-1964.). The traditional solvothermal synthesis method has problems such as high equipment requirements, high reaction temperature, long time consumption, and difficult control of product stoichiometric ratio ([6] SeJin Ahn, KiHyun Kim, KyungHoon Yoon. Nanoparticle derived Cu(In, Ga)Se ₂ absorberlayer for thin film solar cells, Colloids and Surfaces A[J]. 2008(313-314): 171-174.).

Contents of the invention

The object of the present invention is to take copper salt, indium salt, gallium salt, aluminum salt and thiourea, sulfur powder, selenium powder, selenous acid etc. as raw material, adopt microwave-assisted solvothermal method to synthesize Cu(In, Ga)Se ₂ , CuInS ₂ , CuInSe ₂ , Cu(In, Ga)(Se, S) ₂ , CuAlSe ₂ , Cu(In, Al)Se ₂ , Cu(In, Ga, Al)Se ₂ and other semiconductor materials, and the above materials combined composite material. The microwave field has a certain activation effect on the reactants, and microwave heating can ensure the uniform temperature field of the reaction system.

The specific steps are:

Add the metal salt and the sulfur source or the selenium source into the beaker according to the molar ratio of the expected product, then add the solvent, mix evenly, and pour it into the polytetrafluoroethylene reaction kettle. After the reaction kettle is sealed, it is heated in the microwave field to a rated temperature of 100-230°C and then kept for a rated time of 10min-120min; the reaction temperature and reaction time required for the reaction can be precisely controlled by the parameters of the microwave generator; the reaction The final mixture is subjected to centrifugal washing and vacuum drying to obtain the target powder; the chemical composition of the powder is controlled by the ratio of the added raw materials, and the structure of the powder is jointly determined by the ratio of raw materials, synthesis temperature and reaction time.

The solvent is one or more of water, ethylenediamine, ethylene glycol, hydrazine and ethanol;

The metal salt is one or more of metal salts of Cu, In, Ga and Al;

The sulfur source is thiourea or sulfur powder;

The selenium source is selenium powder or selenous acid.

The invention provides a solvothermal preparation process with simple operation and strong reaction activation ability, and the process has the characteristics of fast synthesis reaction speed, strong reproducibility, thorough reaction and the like. This process is based on the heating and activation of the microwave field, which greatly reduces the reaction temperature and shortens the reaction time compared with the traditional high-pressure solvothermal synthesis process; it also enables some reactions that cannot be carried out in the traditional high-pressure solvothermal synthesis to proceed smoothly. In addition, the microwave-assisted solvothermal synthesis process to prepare CuIn _1-x Ga _x Se ₂ and other semiconductor material nanopowders has the advantages of small grain size, pure phase, and precise control of the stoichiometric ratio of the phase.

Description of drawings

Figure 1 is a flow chart of the synthesis process of the present invention.

Fig. 2 is a SEM image of CuIn _0.5 Ga _0.5 Se ₂ nanopowder synthesized by microwave solvothermal in Example 1 of the present invention.

Fig. 3 is an XRD diffraction pattern of CuIn _0.5 Ga _0.5 Se ₂ nanopowder synthesized by microwave solution heat in Example 1 of the present invention.

Fig. 4 is the SEM diffraction pattern of CuInS ₂ nanopowder synthesized by microwave solvothermal in Example 3 of the present invention.

Fig. 5 is an XRD diffraction pattern of CuInS ₂ nanopowder synthesized by microwave solvothermal in Example 3 of the present invention.

Fig. 6 is an XRD diffraction pattern of CuInSe ₂ nanopowder synthesized by microwave solvothermal in Example 4 of the present invention.

Fig. 7 is the SEM diffraction pattern of CuInSe ₂ nanopowder synthesized by microwave solvothermal in Example 4 of the present invention.

Detailed ways

Embodiment 1: (synthesis of CuIn _0.5 Ga _0.5 Se ₂ powder)

Using CuCl ₂ 2H ₂ O, InCl ₃ 4H ₂ O, GaCl ₃ , and Se powder as raw materials, weigh 0.17045g CuCl ₂ 2H ₂ O and 0.146575g InCl ₃ in molar ratio 1:0.5:0.5:2 Add 4H ₂ O, 0.08804g GaCl ₃ , and 0.15792g Se powder into the microwave reactor, add 20ml of ethylenediamine; close the reactor and put it into the microwave instrument, set the parameters of the microwave: heating power 400W, heating time is 15min, the reaction temperature is 230°C, and the reaction time is 120min. After the reaction is over, cool naturally to below 100°C, transfer the reaction solution from the microwave reactor to a centrifuge tube, carry out centrifugal washing and separation of the product, and wash it several times with distilled water and absolute ethanol. Vacuum drying at 80° C. for 8 hours in a vacuum drying oven to obtain CuIn _0.5 Ga _0.5 Se ₂ nanopowder. The phase of the sample analyzed by XRD is pure CuIn _0.5 Ga _0.5 Se ₂ , and analyzed by SEM, the powder presents a granular shape with relatively uniform particle size distribution, and the particle size is as small as 100-200nm.

Embodiment 2: (synthesis of CuIn _0.7 Ga _0.3 Se ₂ powder)

Using CuCl ₂ 2H ₂ O, InCl ₃ 4H ₂ O, GaCl ₃ , and Se powder as raw materials, weigh 0.17045g CuCl ₂ 2H ₂ O and 0.087945g InCl ₃ in molar ratio 1:0.3:0.7:2 Add 4H ₂ O, 0.123256g GaCl ₃ , and 0.15792g Se powder into the microwave reactor, add ethylenediamine 20ml; close the reactor and put it into the microwave instrument, set the parameters of the microwave: heating power 400W, heating time is 15min, the reaction temperature is 230°C, and the reaction time is 60min. After the reaction is over, cool naturally to below 100°C, transfer the reaction solution from the microwave reactor to a centrifuge tube, carry out centrifugal washing and separation of the product, and wash it several times with distilled water and absolute ethanol. Vacuum drying at 80° C. for 8 hours in a vacuum drying oven to obtain CuIn _0.7 Ga _0.3 Se ₂ nanopowder. The phase of the sample analyzed by XRD is pure CuIn _0.3 Ga _0.7 Se ₂ , and analyzed by SEM, the powder presents a granular shape with relatively uniform particle size distribution, and the particle size is as small as 100200nm.

Embodiment 3: (the synthesis of CuInS ₂ powders)

Using CuCl ₂ 2H ₂ O, InCl ₃ 4H ₂ O, and thiourea (CH ₄ N ₂ S) as raw materials, weigh 0.17045g CuCl ₂ 2H ₂ O, 0.29318g InCl ₃ in a molar ratio of 1:1:2 4H ₂ O, 0.15224g thiourea, put into the microwave reaction kettle, add 20ml of ethylene glycol; close the reaction kettle and put it into the microwave instrument, set the microwave parameters: heating power 400W, heating time 10min, reaction temperature The temperature is 190°C, and the reaction time is 60 minutes. After the reaction is over, cool naturally to below 100°C, transfer the reaction solution from the microwave reactor to a centrifuge tube, carry out centrifugal washing and separation of the product, and wash it several times with distilled water and absolute ethanol. Vacuum drying at 80° C. for 8 hours in a vacuum drying oven to obtain CuInS ₂ nanopowder. The sample was analyzed by XRD as CuInS ₂ , and by SEM analysis, the powder particles were mainly composed of spheres and flakes, and the particle size was about 0.2 μm-1 μm.

Embodiment 4: (the synthesis of CuInSe ₂ powder)

Using CuCl ₂ 2H ₂ O, InCl ₃ 4H ₂ O, and selenous acid as raw materials, weigh 0.17045g CuCl ₂ 2H ₂ O, 0.29318g InCl ₃ 4H ₂ O, 0.25794g in a molar ratio of 1:1:2 Selenous acid, add in the microwave reactor, add 2ml hydrazine and 20ml ethylene glycol; Seal the reactor and put it into the microwave instrument, set the microwave condition parameters: heating power 400W, heating time is 10min, reaction temperature is 170°C, the reaction time is 2h. After the reaction is over, cool naturally to below 100°C, transfer the reaction solution from the microwave reactor to a centrifuge tube, carry out centrifugal washing and separation of the product, and wash it several times with distilled water and absolute ethanol. Vacuum drying at 80° C. for 8 hours in a vacuum drying oven to obtain CuInSe ₂ nanopowder. The sample was analyzed as CuInSe ₂ by XRD, and by SEM analysis, there were sheet-like structure agglomerates with a thickness of about 0.1 μm and spherical particles with a size of about 1 μm.

Embodiment 5: (the synthesis of CuAlSe ₂ powder)

Using CuCl ₂ 2H ₂ O, AlCl ₃ 6H ₂ O, and Se powder as raw materials, weigh 0.17045g CuCl ₂ 2H ₂ O, 0.2413g AlCl ₃ 6H ₂ O, 0.15792g Se in a molar ratio of 1:1:2 powder, put it into the microwave reactor, add ethylenediamine 20ml; close the reactor and put it into the microwave instrument, set the parameters of the microwave: the heating power is 400W, the heating time is 10min, the reaction temperature is 200°C, and the reaction time is 60min . After the reaction is over, cool naturally to below 100°C, transfer the reaction solution from the microwave reactor to a centrifuge tube, carry out centrifugal washing and separation of the product, and wash it several times with distilled water and absolute ethanol. Vacuum drying at 80° C. for 8 hours in a vacuum drying oven to obtain CuAlSe ₂ nanometer powder.

Embodiment 6: (synthesis of CuIn _0.5 Al _0.5 Se ₂ powder)

Take CuCl ₂ ·2H ₂ O, InCl ₃ ·4H ₂ O, AlCl ₃ ·6H ₂ O, Se powder as raw materials, weigh 0.17045g CuCl ₂ ·2H ₂ O, 0.146575g by molar ratio 1:0.5:0.5:2 Add InCl ₃ 4H ₂ O, 0.12067gAlCl ₃ 6H ₂ O, 0.15792g Se powder into the microwave reactor, add 20ml of ethylenediamine; close the reactor and put it into the microwave instrument, set the microwave condition parameters: heating The power is 400W, the heating time is 15min, the reaction temperature is 220°C, and the reaction time is 120min. After the reaction is completed, it is naturally cooled to below 100°C, and the reaction solution is transferred from the microwave reactor to a centrifuge tube, and the product is centrifugally washed and separated. , washed several times by centrifugation with distilled water and absolute ethanol, and dried the centrifuged product in a vacuum oven at 80° C. for 8 hours to obtain CuIn _0.5 Al _0.5 Se ₂ nanopowder.

Embodiment 7: (Cu(In, Ga, Al) Se ₂ synthesis of powder)

Take CuCl ₂ 2H ₂ O, InCl ₃ 4H ₂ O, GaCl ₃ , AlCl ₃ 6H ₂ O, and Se powder as raw materials, weigh 0.17045g CuCl ₂ 2H at a molar ratio of 1:0.5:0.25:0.25:2 ₂ O, 0.146575g InCl ₃ 4H ₂ O, 0.04402g GaCl ₃ , 0.12067g AlCl ₃ 6H ₂ O, 0.15792g selenium powder, put into the microwave reactor, add ethylenediamine 20ml; close the reactor and put it in the microwave In the instrument, set the parameters of the microwave conditions: heating power 400W, heating time 15min, reaction temperature 220°C, reaction time 120min, after the reaction, naturally cool to below 100°C, transfer the reaction solution from the microwave reactor into a centrifuge tube, the product was subjected to centrifugal washing and separation, several times of centrifugal washing with distilled water and absolute ethanol, and the product after centrifugal washing was vacuum-dried at 80°C in a vacuum oven for 8 hours to obtain Cu(In, Al, Ga ) Se ₂ nanometer powder.

Claims (1)

1. the preparation method of microwave-secondary solvent thermal synthesis 1-III-VI family semiconductor material nano powder is characterized in that concrete steps are:

In metal-salt and sulphur source or the mole proportioning adding beaker of selenium source by the expection product, add solvent then, pour into after mixing in the tetrafluoroethylene reactor; The airtight back of this reactor heat temperature raising in microwave field is incubated 10min-120min time rating after temperature rating 100-230 ℃; Reacting required reaction needs temperature and reaction times accurately to be controlled by the parameters setting of microwave generator; Obtain target powder after reaction back mixture process centrifuge washing, the vacuum-drying; The powder chemical constitution is by adding proportioning raw materials control, and the structure of powder is by synthesis temperature and the common decision of reaction times control;

Described solvent is one or more in water, quadrol, ethylene glycol, diamine and the ethanol;

Described metal-salt is the metal-salt of Cu, In, Ga and Al;

Described sulphur source is thiocarbamide or sulphur powder;

Described selenium source is selenium powder or selenous acid.

Images