LAUSR

Abstract A comparative study on the electrochemical and photoelectrochemical behavior of SnS thin-film electrode in acidic media was carried out to investigate the SnS-electrolyte interface reactions. The cycling voltammetry examinations were performed to characterize the oxidation and reduction reactions during electrochemical decomposition of the SnS layer in a background solution of 0.1 M H 2 SO 4 . It was observed the presence of passivating oxide-hydroxide layers on the surface on SnS films and studied dynamics of its formation. The corresponding interface reactions were discussed in details and compared with state-of-the-art in similar researches. Photoelectrochemical measurements show that the decrease of photoactivity of SnS is caused mainly by tin hydroxide ultra-thin layer formation on the SnS surface. On the other hand, after electrochemical reduction of the passivating hydroxide layer the photoactyvity increase is observed e.g. electrochemical oxidation at +1200 mV vs. SCE forms on the surface of SnS ultra-thin SnO layer and increases photoactivity almost 4 times. In this paper, special attention is paid to modification of SnS photoabsorber interface by the electrochemical treatment.