Electrodeposition of Fe-doped Sb2Se3 thin films for photoelectrochemical applications and study of the doping effects on their properties

Abstract

Sb2Se3 (SSe) has been highlight as a low-cost, less complex, low toxicity, and earth-abundant photovoltaic (PV) absorber not only because of its excellent properties but also because of its demonstrated 5.6% certified efficiency and decent device stability. An understanding of the effects of intentional dopants on the properties of this material would help to further improve SSe PV devices. In this work, Fe-doped SSe thin film was obtained by electrodeposition at different levels of doping, which is an easy, cheap, and scalable technique. At the studied levels, this dopant caused low influence in band gap and morphologic-structural properties of the films; however, it did impact their electronic properties and photoactivity toward hydrogen gas evolution. The film obtained from a deposition bath composed of 5% of Fe presented a photocurrent similar to that shown by the undoped film, despite showing a carrier density that was three orders of magnitude higher. This behavior makes us believe that, compared to the undoped film, a photovoltaic device made with this 5% Fe-doped film would have a higher fill factor and efficiency.