TWI402996B - A simple manufacture process to obtain near stoichiometric cuxzn snsy(czts) thin films used for solar cells - Google Patents

Description

Method for preparing Cu x ZnSnS y (CZTS) film of solar cell by using copper zinc tin (CuZnSn) alloy

The invention relates to a method for preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell by using a copper zinc tin (CuZnSn) alloy, in particular to a process of a (Cu ₂ ZnSnS ₄ ) film.

In the current limited energy environment, solar cells are gradually paid more attention to many industries, and most of the solar cells are currently silicon wafer solar cells, mainly based on silicon wafers, which have better conversion efficiency, lower equipment, and higher production efficiency. Fast and easy to achieve yield advantages. However, due to the raw material factor, that is, the relative lack of polycrystalline silicon materials and the rising cost, especially when manufacturing large-area power generation modules, the relative cost factor is more obvious.

Therefore, under the continuous research and development in the market, there are gradually so-called "thin film solar cells", which can be fabricated on different and diverse substrates, such as soft and tough plastic substrates (or glass, or other plates), so they can be quite scratched. Sex comes in a variety of environments. Moreover, thin film solar cells require a relatively low thickness for forming a photoelectric effect on plastic, glass or other sheets, and can be relatively economically saved under the same light receiving area.

Among the various types of thin film solar cells, in addition to tantalum thin film solar cells, the development of copper indium gallium selenide Cu(In,Ga)Se ₂ (CIGS) thin film solar cells has also achieved quite good results, but this thin film solar cell faces Among the constituents of the material, indium and gallium (In, Ga) are rare elements, the material price is high, and selenium (Se) has toxicity and other problems. Therefore, zinc and tin (Zn, Sn) with a large content on the earth and less The poisonous sulfur (S) replaces indium and gallium (In, Ga) and selenium (Se), respectively, to produce a non-toxic and low-cost copper-zinc-tin-sulfur (CZTS) solar cell.

Sulfur copper zinc tin (Cu ₂ ZnSnS ₄₎ film is I ₂ -II-IV-VI ₄ group p-type direct bandgap semiconductor material, the crystal structure kesterite structure (kesterite structure), the energy gap is about 1.4 1.5 electron volts, its wavelength is about 827~886nm), refractive index 2.07 (refractive index), lattice constant: a=0.5426nm, c=1.0848nm, copper-zinc-tin-sulfur (Cu ₂ ZnSnS ₄ ) film absorbs light Good in properties, the absorption coefficient in the visible light range is greater than 10 ⁴ cm ^-1 , so only a small thickness of a few μm can absorb most of the incident light, plus good thermal stability, so it is quite suitable as The use of high efficiency thin film solar cell absorber layers.

Among the various preparation techniques for copper-zinc-tin-sulfur (Cu ₂ ZnSnS ₄ ) solar cell films, physical deposition is widely used, and copper, zinc, tin, and three-layer metal film deposits are separately ordered in three steps. There are also three kinds of plating sources (copper, zinc, tin) for metal film deposition at the same time, and the obtained metal film deposits are subjected to a vulcanization process to obtain a copper zinc tin sulphur (CZTS) solar cell film. The process of metal film deposits is complicated and difficult to control, and the quality of the copper-zinc-tin-sulfur (CZTS) solar cell film obtained by subsequent vulcanization process will be difficult to maintain.

In view of the problems of the prior art, the present inventors believe that there should be an improved process, and the technical means for solving the prior art problem of the present invention is to design a Cu _x ZnSnS _y (CZTS) for preparing a solar cell using a copper zinc tin (CuZnSn) alloy. A method of film, wherein 0 ≦ x ≦ 2, 0 ≦ y ≦ 4. The steps include at least: 1. preparing copper, zinc, tin (Cu, Zn, Sn) materials to form copper zinc tin alloy Cu _x Zn _y Sn _z (CZT); 2. using the copper zinc tin alloy as physical The deposition method is performed on the substrate for film deposition, and a copper-zinc-tin deposition film can be obtained on the substrate after deposition; 3. The copper-zinc-tin deposition film is subjected to a vulcanization process to form a copper-zinc-tin-sulfur which can be applied to a solar cell. (Cu _x ZnSnS _y ) film.

The copper zinc tin copper zinc tin _{Cu x Zn y Sn z (CZT} ) based particular embodiment alloy by heating up to a temperature of gold were uniformly mixed to form a copper, zinc, tin (Cu, Zn, Sn) material Cu _x Zn _y Sn _z (CZT) alloy. Since the method can firstly mix copper, zinc and tin materials in proportion to form a uniform alloy, and then deposit the alloy on the substrate in a physical manner to obtain a deposited film, because the copper in the deposited film is obtained. The ratio of zinc and tin has been obtained when the alloy was formed before, so the ratio of the deposited film is easy to control, and the process is relatively simple.

(1) ‧‧‧Copper

(2) ‧ ‧ zinc

(3)‧‧‧ tin

(4) ‧‧‧heater

(5) ‧‧‧ copper zinc tin alloy

(6) ‧‧‧ copper-zinc-tin deposition film

(7) ‧‧‧Substrate

(8)‧‧‧Sulphur-containing components

(9) ‧‧‧ copper zinc tin sulphur film

The first figure is a schematic diagram of the alloy forming material of the present invention.

The second figure is a schematic diagram of the film deposition of the present invention.

The third figure is a schematic diagram of the vulcanization process of the present invention.

The contents, features, and embodiments of the present invention are illustrated by the accompanying drawings. Referring to the first to third figures, the present invention relates to a method for preparing a Cu _x ZnSnS _y (CZTS) film for a solar cell. The steps include:

1. Preparation of copper (1), zinc (2), tin (3) (Cu, Zn, Sn) materials to prepare copper zinc tin alloy (5): the formation of the copper zinc tin alloy (5), mainly can take Copper (1), zinc (2), tin (3) (Cu, Zn, Sn) materials, mixed in proportion, heated by the heater (4) to reach the melting temperature of the alloy, forming a copper-zinc-tin alloy (5) .

2. The copper zinc-tin alloy (5) is deposited on the substrate (7) by physical deposition, and a copper-zinc-tin deposition film (6) can be obtained on the substrate (7) after deposition: This physical deposition refers to a non-chemical manner such as thermal evaporation, plasma sputtering, electron beam evaporation, pulsed laser deposition, and the like. The substrate (7) may be a composite or other material of one or more of plastic, metal, and glass, so that the substrate having the plurality of substrates of the present invention is applicable.

3. Applying the copper-zinc-tin deposition film (6) to a vulcanization process to form copper and zinc which can be applied to solar cells. Tin-sulfur film (9): This vulcanization process refers to heating a substrate (7) containing a copper-zinc-tin deposition film (6) in an environment containing a sulfur component (8) to form copper zinc tin sulfide. Film (9). The sulfur component (8) herein refers to sulfur element or various sulfides which can be used for the vulcanization reaction, and the sulfur component (8) may be in a solid state, a liquid state or a gaseous state.

The specific manufacturing method of the present invention is as follows: in combination with the first figure, the copper (1), zinc (2), and tin (3) materials are mixed and mixed in proportion, and then heated by the heater (4) to reach the alloy temperature to form copper. Zinc-tin alloy (5).

Then, as shown in the second figure, a copper-zinc-tin alloy (5) is deposited on the substrate (7) in a physical deposition manner to form a copper-zinc-tin deposition film (6).

Then, as shown in the third figure, the copper-zinc-tin deposition film (6) and the substrate (7) are placed in an environment containing the sulfur component (8), and heated to carry out a vulcanization process to obtain a copper-zinc-tin-sulfur film. (9).

The invention can be used in a relatively simple process, effectively controlling the proportion of the copper-zinc-tin-deposited film, and then applying the vulcanization process to obtain the desired copper-zinc-tin-sulfur solar cell film. The method of the present invention is simple and feasible and has no size limitations.

In summary, since the creation is considered to be in conformity with the patentable requirements, the patent application is filed according to law. However, the above-mentioned findings are a preferred embodiment of the creative industry. The equal changes in the scope of patent application for this creation are all within the scope of the claim.

Claims (7)

A method for preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell using a copper zinc tin (CuZnSn) alloy, wherein 0 ≦ x ≦ 2, 0 ≦ y ≦ 4, the steps of which at least include: A. taking copper, zinc, respectively Tin (Cu, Zn, Sn) materials form a uniformly mixed copper-zinc-tin Cu x Zn y Sn z (CZT) alloy by heating to a common gold temperature; B The copper zinc-tin alloy is deposited on the substrate by physical deposition, and a copper-zinc-tin deposition film can be obtained on the substrate after deposition; C. the copper-zinc deposition film is applied to the vulcanization process to form A copper-zinc-tin-sulfur film that can be applied to solar cells. A method for preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell using a copper zinc tin (CuZnSn) alloy as described in claim 1, wherein the heating is directly heated or high-frequency electromagnetic radiation heating, and the heating is performed. The environment can be a general atmospheric environment, under vacuum, or by adding a blunt gas. The method of preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell by using a copper zinc tin (CuZnSn) alloy as described in claim 1 of the patent application, the physical deposition of the B step includes a thermal evaporation method, and a plasma sputtering method. , electron beam evaporation or pulsed laser deposition. The method of preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell by using a copper zinc tin (CuZnSn) alloy as described in claim 1, the vulcanization process of the C step includes including Cu _x Zn _y Sn _z (CZT) The substrate on which the thin film is deposited is heated in an environment containing a sulfur component to form a copper zinc tin sulfide Cu _x ZnSnS _y (CZTS) film, and the sulfur component includes sulfur element or vulcanization which can be used for vulcanization reaction. And the sulfur component is in a solid or gaseous state. A method of preparing a ZnSnS _y (CZTS) film of a solar cell using a copper zinc tin (CuZnSn) alloy as described in claim 1, wherein the preparation of the step A is via heating. A method for preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell using a copper zinc tin (CuZnSn) alloy as described in claim 1, wherein the substrate of the step B is selected from the group consisting of plastic, metal, and glass. One or more of them are combined. A method of preparing a Cu _x ZnSnS _y (CZTS) film of a solar cell using a copper zinc tin (CuZnSn) alloy as described in claim 1, wherein the C step is via heating.