Effects of Sb and Cu doping and precursor flow rate on the structure and composition of SnS thin films fabricated by electrostatic spray deposition

• SnS thin films were obtained using scalable electrostatic spray deposition. • Higher flow rates of source reduced the Sn/S ratio and crystal size, tuning crystallinity. • Sb doping improved crystallinity without forming extra phases in SnS. • Excess Cu doping led to Cu 2 SnS 3 formation as an extra phase in SnS. • Deposition and doping enabled precise control of SnS film composition and quality. In this study, a scalable electrostatic spray deposition (ESD) technique was employed to fabricate SnS thin films, and the effects of the deposition flow rate and impurity doping on their structural properties were systematically investigated. A reduction in the flow rate from 5 to 0.5 mL/h significantly decreased the Sn/S atomic ratio from 1.2 to 0.3, along with a reduction in the crystal size from 120 to 20 nm. The results demonstrate that the crystalline quality and stoichiometry of SnS films can be finely tuned by controlling the deposition kinetics. Furthermore, doping with 20% Sb in the precursor solution improved the crystallinity without introducing extra phases, indicating effective substitution at Sn sites. Conversely, Cu doping at the same nominal concentration induced the formation of Cu 2 SnS 3 and other extra phases, indicating the tendency of Cu to form mixed chalcogenide compounds under ESD conditions. These findings demonstrate the capability of ESD for the scalable synthesis of SnS thin films and its potential for precise doping control to analyze complex phase formation in multinary chalcogenide systems.