Carrier control in SnS by doping: A review

Tin sulfide (SnS) is a semiconductor composed of abundant and non-toxic elements and has potential applications as a light absorbing layer in thin-film solar cells and a thermoelectric material. While controlling the carrier type (n- or p-type conduction) and carrier concentration of SnS by impurity doping has been intensively studied both experimentally and theoretically since 2010s, no comprehensive discussion of them has been made. This review is motivated to provide researchers with an overview of SnS doping techniques including following topics. The importance and effects of carrier control on the performance of SnS-based photovoltaics and thermoelectric devices are at first discussed. Subsequently, the electrical property of the undoped SnS resulting from its intrinsic defects are summarized. Also, the characteristics of p- and n-type dopings to SnS with various dopants are summarized and compared with the doping systems to other IV–VI group semiconductors, particularly SnSe. The final section presents a perspective on the current status of research in SnS carrier control and potential future research directions.