The Research Of Different Metal Back Electrode And Encapsulation Performance In CdTe Solar Cells

The cost of solar cells, which is the energy sources on the earth, mainly constraints the development of the solar cells. In order to find one kind of metal back electrode material, which can provide higher conversion efficiency at obviously lower cost, the effects of different metals on properties of CdTe solar cells have been studied. The performances' change of CdTe solar cells before and after encapsulation and stability of Encapsulated CdTe solar cells have also been studied.Ni is suitable to be the back electrode of CdTe solar cells. Its work function of 5.0eV is a little higher than that of Au (4.9eV), so it is easier to form Ohmic contact between semiconductor and Ni. It is more important that the price of Ni is much lower than that of Au; hence it is promising to reduce the cost of CdTe solar cells for the industrialization.In this paper, the effects and mechanism of Ni and Au back electrode on the performances of CdTe solar cells have been studied through experiments. For the back electrode of Ni, Ni/Au, Au/Ni and Au film, only when the Ni film contacts the ZnTe/ZnTe:Cu complex layers, does the conversion efficiency increase with the short current increasing. So it is not only probable that the conversion efficiencies of cells will be increased by 4% at least, but also it is rather promising to reduce cost in large scale manufacturing.By analyzing the AFM images of Au film and Ni film, the dark C-V/I-V cures and the XPS after exploiting the back electrode film, we can conclude that:...