Cadmium-free copper indium gallium selenide thin film solar cell and preparation method of zinc sulfide buffer layer film thereof

Abstract

A method for preparing a cadmium-free copper indium gallium selenide thin film solar cell, comprising the following steps: step 1, forming a back electrode and a copper indium gallium selenide light absorption layer on a substrate in sequence to form a sample; step 2, adding zinc acetate dihydrate Dissolve in absolute ethanol, add a stabilizer, and heat to form a sol; step 3, immerse the sample in the sol for 5 to 10 seconds, and then lift the sample from the sol; step 4, put the sample Dry at 100-200° C. for 30 minutes to form a zinc oxide film on the surface of the sample; Step 5, put the sample into a selenization chamber and perform annealing treatment under an atmosphere of hydrogen sulfide to convert the zinc oxide film into a zinc sulfide buffer layer film; And step six, sequentially forming a barrier layer and a window layer on the zinc sulfide buffer layer film. Due to the high temperature in the annealing process of the above preparation method, the crystalline quality of the thin film can be improved. The invention also provides a preparation method of the zinc sulfide buffer layer film.

Description

【Technical field】 [0001] The invention relates to a cadmium-free copper indium gallium selenium thin film solar cell and a preparation method of the zinc sulfide buffer layer. 【Background technique】 [0002] Copper Indium Gallium Selenide (Cu(In,Ga)Se 2 , referred to as CIGS) thin-film solar cell is a new type of solar cell developed in the late 1980s, and its excellent performance has attracted widespread attention. The typical structure of copper indium gallium selenide thin film solar cells is a multilayer film structure, including: metal gate (Al) / transparent electrode (AZO) / window layer (ZnO) / buffer layer (CdS) / light absorption layer (CIGS) / Back electrode (Mo) / glass. [0003] Although the thickness of the buffer layer is only 50nm, it is crucial for CIGS cells. The buffer layer can form a heterojunction with the CIGS absorber layer so as to separate the photogenerated carriers and protect the absorber layer from being damaged when the upper electrode is pla...

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Problems solved by technology

[0007] In the preparation of CIGS solar cell, the method of obtaining ZnS thin film is very important, at present as the preparation of the ZnS buffer layer of solar cell mostly adopts CBD method, this method has the following problems: 1) there is homogeneous precipitation during thin film deposition, in formation At the same time as ZnS, Zn(OH) is also generated 2 , Zn(OH) 2 Mixed into ZnS film, resulting in a non-ZnS pure phase of the film

The ZnS thin film with impurity has poor adhesion and is easy to crack; 2) in the preparation process of ZnS thin film, if the distribution of solution temperature concentration is uneven and the instability of stirring rate will also lead to poor reproducibility, in the preparation of large area Film uniformity is more difficult to control

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