CN102583510A

CN102583510A - Microwave-synthesis method for preparation of copper-zinc-tin-sulphur (CZTS) nanoparticles

Info

Publication number: CN102583510A
Application number: CN2012100544425A
Authority: CN
Inventors: 沈鸿烈; 王威
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2012-03-05
Filing date: 2012-03-05
Publication date: 2012-07-18
Also published as: CN102826594A

Abstract

The invention relates to a low-cost microwave synthesis method for preparation of a material, namely Cu2ZnSnS4, of an absorbing layer of a solar cell, which belongs to the technical field of solar cell materials and devices. According to the invention, suitable reaction solution is prepared, and then the solution is put into a microwave oven to be heated to obtain Cu2ZnSnS4 nanoparticles. The microwave synthesis method has the advantages that raw materials are rich in source and low in cost, complicated equipment is not needed, the preparation process is simple, the preparation cost is low, and components of the nanoparticles are controllable. The prepared copper-zinc-tin-sulphur (CZTS) nanoparticles can be dispersed into ethanol or ethylene glycol to form ink, and the ink is coated to form a thin film, so that the CZTS thin film solar cell is manufactured.

Description

The method of the synthetic copper-zinc-tin-sulfur nano particle of a kind of microwave

Technical field

What the present invention relates to is material of a kind of nano photoelectric technical field and preparation method thereof, is specifically related to a kind of compound method of copper-zinc-tin-sulfur nano particle.

Background technology

Global energy shortage, environmental pollution, climate warming are just day by day seriously perplexing human society.Seek green substitute energy, realize Sustainable development, become the problem that countries in the world face jointly.In the long run, renewable energy source will be following human main energy sources source.In the utilization of the renewable energy source of new development, the tool potentiality of solar cell.

Because the shortage of global silicon materials and high preparation cost, thin film solar cell has caused people's extensive concern, has become scientific worker's research center of gravity.Thin film solar cell is divided into silicon-based thin film solar cell and compound film solar cell, and as the representative of compound film battery, CIGS (the copper indium is sowed selenium) thin film solar cell has been obtained significant progress.By the end of the end of the year 2010 its high conversion efficiency reached 20.3%, but the sky high cost of the toxicity of its component Se and In, Ga is but seriously restricting the development of CIGS.In order to seek a kind of nontoxic cheapness and solar cell material efficiently, people have passed through unremitting effort and exploration.

Cu ₂ZnSnS ₄(being designated hereinafter simply as CZTS) is one type of custerite structure (kesterite) compound semiconductor, and the CIGS of its structure and yellow copper structure is similar, can regard as with In, Ga, Se among Zn, Sn and the S difference replaced C IGS.Because In and Ga are precious metal, and Se has certain toxicity, so CZTS compares CIGS and has bigger advantage aspect cost and the environmental friendliness.The optical band gap of CZTS film is near 1.5eV, and is better with the response of solar spectrum, is suitable as very much the light absorbing zone in the solar cell.Big (the visible light wave range uptake factor 10 of the photoabsorption coefficient of CZTS ⁴Cm ^-1-10 ⁵Cm ^-1), only need 1 μ m thickness can absorb sunshine fully, be fit to the preparation thin film solar cell, reserves all enrich and nontoxic on the component earth of CZTS in addition.Therefore, CZTS receives people's attention in recent years gradually as a kind of solar cell absorbing layer materials, is that the solar cell efficiency of conversion of absorption layer reaches 6.8% at present with CZTS, and replaces Cu with a part of Se ₂ZnSnS ₄In the Cu of S ₂ZnSn (S, Se) ₄(CZTSSe) battery efficiency can reach 9.6%.Therefore this novel solar cell has good application prospects and huge commercial value.

Prepare Cu at present ₂ZnSnS ₄The method of sun absorbing material mainly contains adopting non-vacuum process such as sputter, evaporation equal vacuum technology and electrochemical deposition, spin coating.Preparation technology compares with vacuum, and adopting non-vacuum process need not expensive vacuum apparatus, therefore on cost, has more advantage.And preparation Cu ₂ZnSnS ₄Nano particle mainly is to adopt solvent-thermal method, and it is longer that this method prepares the required reaction times of material, and energy consumption is higher.Microwave process for synthesizing prepares the CZTS nano particle and only needs 5-30min, has greatly shortened the preparation cycle of material, and energy consumption is low, and the preparation process is nontoxic, pollution-free, and output is big.

Summary of the invention

The present invention proposes a kind of compound method of copper-zinc-tin-sulfur nano particle; This method needing no vacuum equipment reduces production costs, and preparation cycle is short; Be fit to large-scale industrialization production; The used material of preparation copper-zinc-tin-sulfur nano particle all is nontoxic, pollution-free and cheap, and the production cost that this has extremely reduced solar cell has a good application prospect.

Cu involved in the present invention ₂ZnSnS ₄The preparation method of nano particle realizes through following technical scheme, specifically comprises following step:

A kind of compound method of copper-zinc-tin-sulfur nano particle is characterized in that, comprises the steps:

(1). at first be the preparation of solution; Mantoquita, pink salt, zinc salt and sulphur source are joined in the organic solvent, with magnetic stirrer it is fully dissolved and obtain settled solution.Wherein said cupric salt concentration is 0.03 M-0.06 M, and stannous salt concentration is 0.02 M-0.05 M, and divalent zinc salt concentration is 0.02 M-0.05 M; The concentration of sulfonium ion is 0.05 M-0.1 M;

(2). the solution that step (1) obtains is put in the microwave oven; Microwave power is 100-800W, and the microwave time is 5-30min, obtains Cu ₂ZnSnS ₄Nanoparticles solution;

(3). step (2) is separated from solution with whizzer to the nano particle that gets, and centrifugal speed is 6000 r/min, and the time is 10min, repeatedly cleans with ultrapure water and ethanol again, finally obtains Cu ₂ZnSnS ₄Nano particle.

Wherein the said cupric salt of step (1) is a kind of or its combination in cupric chloride, copper sulfate, cupric nitrate or the venus crystals.

The described divalent zinc salt of step (1) is a kind of or its combination in zinc chloride, zinc sulfate, zinc nitrate or the zinc acetate.

Stannous salt described in the step (1) is a kind of or its combination in tindichloride, tin acetate, stannous octoate, methyl ethyl diketone Tin tetrabromide or the methyl ethyl diketone tin chloride.

Sulphur source described in the step (1) is a kind of or its combination in thioacetamide, Sulfothiorine, thiocarbamide or the sodium sulphite.

Organic solvent described in the step (1) is a kind of in ethanol, terepthaloyl moietie or the oily ammonia.

The principle of the invention:

Microwave heating is through material Semi-polarity molecule and microwave electromagnetic field interactions; Polar molecule polarizes and the alternation orientation with adding the alternating electromagnetic field change of polarity under the alternating electromagnetism field action; Polar molecule is that electromagnetic energy is converted into heat energy because of frequently turning to frictional dissipation each other.Metal-salt that adds and sulphur source form complex body, can change copper-zinc-tin-sulfur into through the microwave heating complex body.

Beneficial effect

With existing preparation Cu ₂ZnSnS ₄The compared with techniques of nano particle, the present invention has following several beneficial effect: the present invention adopts microwave process for synthesizing to belong to antivacuum chemical synthesis process, has avoided adopting the expensive problem of vacuum apparatus; Present technique is compared with traditional solvent-thermal method and the fast advantage of speed of response is arranged, and solvent-thermal method prepares Cu ₂ZnSnS ₄Nano particle needs tens hours, and present technique only needs 5-30min, has significantly reduced energy loss; This preparation method can adjust element ratio arbitrarily through regulating processing parameter; The output of the nano particle of present technique preparation is bigger, is convenient to industrialization production.

Description of drawings

Fig. 1 is Cu prepared among the embodiment 1 ₂ZnSnS ₄The X ray diffracting spectrum of nano particle.

Fig. 2 is Cu prepared among the embodiment 1 ₂ZnSnS ₄The absorption spectrum collection of illustrative plates of nano particle.

Fig. 3 is Cu prepared among the embodiment 1 ₂ZnSnS ₄The ESEM picture of film.

Embodiment

Below in conjunction with embodiment the present invention is further described, but should not limit protection scope of the present invention with this.

Embodiment 1

Take by weighing 1 mmol zinc chloride, 1 mmol tindichloride, 2 mmol cupric chlorides and 4 mmol Sulfothiorine and be dissolved in the terepthaloyl moietie of 50 mL, put in the microwave oven after stirring and heat, microwave power transfers to 800 W; React 5 min; Spinning, the ultrapure water washing promptly obtains Cu ₂ZnSnS ₄The film nano particle.Prepared Cu ₂ZnSnS ₄The X ray diffracting spectrum of nano particle, absorb light collection of illustrative plates and surface sweeping Electronic Speculum picture are respectively like Fig. 1, Fig. 2 and shown in Figure 3.Prepared Cu ₂ZnSnS ₄Nano particle has (112) preferred orientation, and its optical band gap is about 1.5 eV, and nanoparticle size is about 200-400 nm, and the element ratio in the nano particle is Cu:Zn:Sn:S=2.1:1:1.1:4.1.

Embodiment 2

Take by weighing 1 mmol zinc chloride, 1 mmol tindichloride, 2 mmol cupric chlorides and 4 mmol Sulfothiorine and be dissolved in the terepthaloyl moietie of 50 mL, put in the microwave oven after stirring and heat, microwave power transfers to 800 W; React 20 min; Spinning, the ultrapure water washing promptly obtains Cu ₂ZnSnS ₄The film nano particle.

Embodiment 3

Take by weighing 1 mmol zinc chloride, 1 mmol tindichloride, 2 mmol cupric chlorides and 4 mmol Sulfothiorine and be dissolved in the terepthaloyl moietie of 50 mL, put in the microwave oven after stirring and heat, microwave power transfers to 400 W; React 20 min; Spinning, the ultrapure water washing promptly obtains Cu ₂ZnSnS ₄The film nano particle.

Embodiment 4

Take by weighing 1 mmol zinc chloride, 1 mmol tindichloride, 2 mmol cupric chlorides and 4 mmol Sulfothiorine and be dissolved in the ethanol of 50 mL, put in the microwave oven after stirring and heat, microwave power transfers to 800 W; React 5 min; Spinning, the ultrapure water washing promptly obtains Cu ₂ZnSnS ₄The film nano particle.

Embodiment 5

Take by weighing 1 mmol zinc chloride, 1 mmol tindichloride, 2 mmol cupric chlorides and 4 mmol Sulfothiorine and be dissolved in the oleyl amine of 50 mL, put in the microwave oven after stirring and heat, microwave power transfers to 800 W; React 5 min; Spinning, the ultrapure water washing promptly obtains Cu ₂ZnSnS ₄The film nano particle.

Claims

1. the method for the synthetic copper-zinc-tin-sulfur nano particle of microwave is characterized in that, comprises the steps:

It at first is the preparation of solution; Mantoquita, pink salt, zinc salt and sulphur source are joined in the organic solvent, with magnetic stirrer it is fully dissolved and obtain settled solution;

Wherein said cupric salt concentration is 0.03 M-0.06 M, and stannous salt concentration is 0.02 M-0.05 M, and divalent zinc salt concentration is 0.02 M-0.05 M; The concentration of sulfonium ion is 0.05 M-0.1 M;

The solution that step (1) obtains is put in the microwave oven; Microwave power is 100-800W, and the microwave time is 5-30min, obtains Cu ₂ZnSnS ₄Nanoparticles solution;

Step (2) is separated from solution with whizzer to the nano particle that gets, and centrifugal speed is 3000-10000 r/min, and the time is 3-10 min, repeatedly cleans with ultrapure water and ethanol again, finally obtains Cu ₂ZnSnS ₄Nano particle.

2. the method for the synthetic copper-zinc-tin-sulfur nano particle of a kind of microwave according to claim 1 is characterized in that the described cupric salt of step (1) is a kind of or its combination in cupric chloride, copper sulfate, cupric nitrate or the venus crystals.

3. the method for the synthetic copper-zinc-tin-sulfur nano particle of a kind of microwave according to claim 1 is characterized in that the described divalent zinc salt of step (1) is a kind of or its combination in zinc chloride, zinc sulfate, zinc nitrate or the zinc acetate.

4. the method for the synthetic copper-zinc-tin-sulfur nano particle of a kind of microwave according to claim 1; It is characterized in that the stannous salt described in the step (1) is a kind of or its combination in tindichloride, tin acetate, stannous octoate, methyl ethyl diketone Tin tetrabromide or the methyl ethyl diketone tin chloride.

5. the method for the synthetic copper-zinc-tin-sulfur nano particle of a kind of microwave according to claim 1 is characterized in that the sulphur source is a kind of or its combination in thioacetamide, Sulfothiorine, thiocarbamide or the sodium sulphite.

6. the method for the synthetic copper-zinc-tin-sulfur nano particle of a kind of microwave according to claim 1 is characterized in that, organic solvent is a kind of in ethanol, terepthaloyl moietie or the oily ammonia.