Role of Nitrogen Doping in Defect Control and Phase Stability of Sulfurized SnS Thin Films

Tin sulfide (SnS) thin films were investigated to clarify the role of nitrogen (N) doping in defect control and phase stability during sulfurization. In this study, SnS thin films prepared via reactive sputtering with N 2 addition followed by sulfurization were examined with respect to their structural and electrical properties. X‐ray photoelectron spectroscopy confirmed the presence of N species in the films, suggesting N incorporation. X‐ray diffraction and Raman spectroscopy revealed that moderate N doping ( p (N 2 ) = 1%) slightly degraded crystallinity but effectively suppressed the formation of undesirable n‐type secondary phases such as Sn 2 S 3 and SnS 2 . Hall measurements showed that N‐doped films sulfurized above 450°C exhibited higher hole concentrations than undoped films, suggesting that N may contribute to acceptor‐like defect formation under high‐temperature sulfurization conditions. Analysis of the carrier concentration–mobility relationship indicated a transition from grain boundary–limited to ionized impurity–limited transport at high carrier concentrations. These results demonstrate that controlled N doping plays a significant role in defect activation and phase stabilization in sulfurized SnS thin films, providing useful insights for defect engineering in chalcogenide semiconductors.