A single-precursor solution approach is developed for depositing stoichiometric BiSI thin films featuring pure paraelectric orthorhombic (Pnam) phase. The compact and homogenous films are composed of flake-shaped grains oriented anti-planar to the substrate and display a sharp optical transition corresponding to a bandgap of 1.57 eV. Optical and Raman signatures of the thin films are rationalized using the quasiparticle G0W0@PBE0 and Density Functional Perturbation Theory calculations. Electrochemical impedance spectroscopy revealed n-type doping with valence and conduction band edges located at 4.6 and 6.2 eV below vacuum level, respectively. Planar BiSI solar cells are fabricated with the architecture: glass/FTO/SnO2/BiSI/F8/Au, where F8 is poly(9,9-din -octylfluorenyl-2,7-diyl), showing record conversion efficiency of 1.32% under AM 1.5 illumination.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.