Electrodeposition of low-cost SnS films with increasing carrier concentration and mobility by aluminum doping and texture adjustment

SnS is considered being a promising thermoelectric material because it has the same crystal structure as that of SnSe which has excellent thermoelectric properties. However, the low electronic transmission properties confine its performances. The difficult preparation and poor mechanism property of SnS single crystal also confined its commercial application. In this paper, we successfully doped aluminum into the SnS films by a simple one-step co-deposition method. We obtained compact aluminum-doped SnS films with orthogonal crystal structure, which was caused by the properly controlled composition. The carrier concentration of the aluminum-doped SnS films was successful increased by the increase in Al content. The resistivity was further decreased by the additives in the electrolytes because the additives changed the texture orientation and texture coefficient, which caused the change of carrier mobility. When CTAB was added into the electrolytes, the strong (200) texture formed in the aluminum-doped film which caused a relatively large carrier mobility. The combination of the large carrier mobility and concentration determined the resistivity as small as 91.82 Ω·cm. The results proved that aluminum doping can effectively increase the carrier concentration of SnS films, and the simultaneous carrier mobility decrease can be compensated by additives. The aluminum doping and additive application pave an effective way to promote the electric transition properties of SnS films which is profitable for its thermoelectric characters. And the simplicity of the co-deposition method of aluminum doping and texture adjustment exhibits a potential of commercial application.