Photosensitive antimony triiodide thin films by rapid iodization of chemically deposited antimony sulfide

Abstract

In this work, we report the synthesis of antimony triiodide (SbI3) thin films via a simple and facile process of iodizing chemically deposited antimony sulfide (Sb2S3) thin films. Density functional theory (DFT) calculations were employed to determine the electronic band structure of SbI3. The crystal structure, morphology, composition, and optoelectronic properties of SbI3 films formed at different conditions were investigated. The structural and morphological analyses revealed hexagonal SbI3 thin films with compact and granular surface morphology. EDS analysis showed a nearly stoichiometric composition of the SbI3 phase. The experimentally estimated direct bandgaps were in the range of 2.3−2.1 eV in correlation with the DFT calculations. Further, stable photodetector devices were fabricated using the SbI3 films. The devices displayed good reproducibility and a significant response to the visible light. This novel strategy for the synthesis opens a new opportunity for this metal iodide based optoelectronic and photovoltaic devices.