Preparation And Structural Studies Of A Novel Solar Energy Cell Material SnS Thin Films

SnS thin film is a nontoxic semiconductor material. It has direct energy band gap around 1. 2~1. 5eV and indirect energy band gap around 1. 0~1. 1eV, which is close to the optimum value of the solar radiation. And it has high energy conversion. It is an important material used in the solar energy cells as absorption layer. In this paper, three methods have been employed to deposit SnS thin films.Thin films of SnS were prepared by the chemical bath deposition method. And the chemical bath for deposition of SnS thin films was constitute of triethanolamine SnCl2 2H2O, NH4Cl.NH4OH and triethanolamine. The reaction mechanism of chemical deposition was studied, and the optimum reaction condition was obtained. The deposition of SnS thin films by chemical bath with ultrasonication was studied.The successive ionic layer adsorption and reaction method was used to prepare SnS thin films under optimized condition: the concentration of SnCl2 is 0. 2M/1, the concentration of Na2S is 0.1M/l, the temperature of SnCl2 solution is 70C and Na2S is room temperature.The reaction mechanism of chemical bath is been studied. It was found thatthe concentration of TEA and ammonia is very important for the SnS thin film quality.XRD and SEM were employed to study the structure of thin films. XRD results imply that thin films deposited by three methods were SnS thin films. SnS thin films deposited by those methods on glass substrate are amorphous or consist of fine grains. SEM results imply that the surface of thin films deposited by chemical bath method is correlate to the reaction conditions. Surface of SnS thin films deposited by chemical bath method are coarse than thin films deposited by chemical bath with ultrasonication method and successive ionic layer adsorption and reaction method.