Papers by Keyword: SnS:Ag Thin Films

Abstract: Silver-doping in SnS films can improve the semiconducting properties of SnS films. Based on our previous research, SnS:Ag thin films were deposited on ITO coated glass by pulse electro-deposition in order to study their structural, optical and electrical properties. SnS:Ag thin films were characterized with X-ray diffraction (XRD) , Scanning Electron Microscope (SEM) and some other methods. The primary composition of the films is SnS, but maybe there is a little quantity of SnS2, Ag8SnS6 and other compounds. The doped films exhibit good crystallization with big grain size. They have an optical gap of 1.66~1.89eV and a high absorption coefficient (α＞5×104cm-1). Hall measurement has shown that all the samples are of p-type conduction with low resistivity of the order of 10-3Ω•cm, and the carrier concentration increases to 1019cm-3 after Ag-doping. In conclusion, the semiconducting properties of the SnS films have been improved by silver-doping. Thus, SnS:Ag thin films can be used as solar cells absorbers.

Abstract: SnS and Ag films were deposited on glass substrates by vacuum thermal evaporation successively, then they were annealed in N2 ambience at a temperature of 300 oC for 2h. By controlling the Ag evaporation voltage to roughly alter content of Ag in SnS films, different Ag-doped SnS films were obtained. The microstructures, composition and properties of the films were characterized with X-ray diffraction ( XRD ), atomic force microscopy(AFM) and some other methods. With the increase of Ag evaporation voltage (VAg), there exist new phases of Ag8SnS6 and Ag2S, whose intensity of diffraction peaks increases with the increasing Ag-dopant, and the average roughness of the films varies from 18.7nm to 23.6nm, and grain size increases from 192nm to 348nm. With the increase of VAg, the evaluated direct band gap Eg of the films decreases from 2.28eV(undoped) to 2.05eV (VAg=70V), the carrier concentration value and Hall mobility of the films diminishes from 2.048×1014cm-3 and 25.96 cm2.v-2.s-1 to 1.035×1016 cm-3 and 5.66 cm2.v-2.s-1, respectively; while the resistivity of the films decreases sharply from 1174Ω.cm(undoped ) to 107Ω.cm (VAg=70V ). All the films are of p-type conductivity. The above results show that the semiconducting properties of the SnS films have been improved by silver-doping.