Cadmium sulfide thin film solar cell and preparation method thereof

Abstract

The invention belongs to the field of novel energy source materials and devices, in particular relates to a preparation method of a semiconductor film solar cell and provides a CdS homojunction solar cell structure, wherein Cd2SnO4 serves as a transparent conducting layer, n type CdS serves as a window layer, Zn2SnO4 serves as a buffering layer material between the transparent conducting layer and the window layer, and p type CdS serves as an absorbing layer. On the basis of the CdS homojunction solar cell structure, a CdS solar cell is prepared by a dry process. Namely, the preparation method comprises the following steps of: performing radio-frequency sputtering on the borosilicate or aluminosilicate glass to form the transparent conducting layer Cd2SnO4; performing radio-frequency sputtering to form the buffering layer Zn2SnO4; performing radio-frequency sputtering to form the n type CdS serving as the window layer; depositing copper-doped CdS at room temperature through physical gas phase method and performing post treatment to form the p type CdS serving as the absorbing layer; or directly growing the p type copper-doped CdS serving as the absorbing layer at a certain temperature through the physical gas phase method; and depositing a metal electrode and connecting a lead. Through the structure and the process, sun light can be better collected and used; p type doping treatment can be effectively performed on the CdS; influences caused by lattice mismatch and interface state are eliminated; and then higher photoelectric conversion efficiency is achieved.

Description

technical field [0001] The invention belongs to the field of new energy materials and devices, and in particular relates to a method for preparing a semiconductor thin film solar cell. Background technique [0002] Cadmium sulfide (CdS) is an important photosensitive semiconductor widely used in the field of optoelectronics, such as photoconductive gas sensors, photocells, semiconductor lasers, infrared detectors, solar cells, etc. [0003] An important application of CdS in the photovoltaic field is to make CdS solar cells. This type of solar cell is prepared with CdS as the base material. Because of its spectral response and solar spectrum match very well, it is suitable for solar cells and can obtain relatively high theoretical conversion. efficiency (see figure 1 ). In the 1950s, the structure of CdS solar cells that received great attention in the field of photovoltaics was: CdS / Cu / electrode, and its preparation method usually uses properly doped n Type CdS single cr...

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Problems solved by technology

Formed by thermal diffusion p Type materials are difficult to determine the position of the barrier region, and CdS has a self-compensation effect, which is not easy to achieve p type doping, so that the prepared CdS is generally n type semiconductor

Therefore, by diffusion treatment to obtain p Type CdS is more difficult

In addition, at high temperature, copper will also diffuse to ITO, which will affect the performance of the front electrode. At the same time, the incomplete diffusion or residue of copper will also affect the transmission of sunlight.

[0004] In addition to the above-mentioned CdS-based solar cells, there is also a CdS-based solar cell made by the "Clevite process", that is, a CdS single crystal or thin film is used as a substrate, impregnated with hot Cu 2 Cl 2 solution, reaction p Type Cu 2 S, so as to obtain heterojunction CdS solar cells. Although the cost of this type of cell is relatively low, the efficiency of the cell is 5-8%, and large-scale production can be achieved, but this type of cell is difficult to control p type compound Cu x The phase of S is easy to produce a mixed phase, and at the same time, the battery is accompanied by a decay phenomenon

[0005] Therefore, the above two batteries have not achieved great development.

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