Electrical properties of doped SnS thin films prepared by vacuum evaporation

Tin sulfide（SnS）has received much attention because of its high absorption coefficient,suitable band-gap and little toxicity.The resistivity of pure-SnS thin film deposited by vacuum evaporation is too high to make solar cell.In order to solve this problem,doped-SnS thin films were fabricated.Sb, Sb₂O₃,Se,Te,In,In₂O₃,Se and In₂O₃ were used as dopant sources.The thickness and conductance of various doped-SnS thin films were measured,and then the resistivities and the ratio of photo-conductivity to dark-conductivity(G_photo/G_dark)of these films were calculated.From the experimental results,Sb is the best dopant source.The resistivity of Sb doped-SnS thin film is reduced by four orders of magnitude and the value of G_photo/G_darkis double.In addition,the influence of Sb doping content on the electrical properties of doped-SnS thin films was also investigated,and the optimum doping content of Sb is 1.3%～1.5% in weight.