Study Of New Back Contact For CdTe Solar Cell

At present, the researches and production of thin film solar cells are the focus in the photovoltaic field. Owing to its optoelectronic and chemical properties, the polycrystalline thin films CdTe could be the ideal absorber materials for high-efficiency, low-cost thin film solar cell. But because of the high work function of p-CdTe thin film, it is difficult for p-CdTe to form a stable ohm contact between p-CdTe and back electrode. In order to solve this issue, surface treatments are applied and back contact layer between CdTe and metal electrode is deposited. Presently, bromine-methanol and nitric-phosphoric acid are the familiar surface treatments solution and ZnTe/ZnTe:Cu complex back contact is used to obtain high efficiency CdTe solar cells.In this article, the influence of nitric-acetic acid etching CdTe polycrystalline thin film and the performance of CdTe solar cells using different structure as back contact layer after surface pretreatment are studied.A thin Te coating is created after nitric-acetic acid etching CdTe film surface. It is observable that the chemistry reaction is mild, and the surface color of CdTe thin film is changed to gray-white, but during the process of etching, little air bubble can be observed. The...