Synthesis of bismuth sulphoiodide thin films from single precursor solution

Bismuth sulphoiodide (BiSI) is considered as an excellent absorber material for toxicity-free photovoltaics (PV). Nevertheless, its applications in thin-film PV are often limited by the lack of pure phase thin-film fabrication techniques. Here, we design a novel precursor composition to fabricate pure phase thin-films by conventional spin-coating route. The as-prepared thin-films are characterized by X-ray diffraction studies, optical absorption spectroscopy, X-ray photoelectron spectroscopy, and transmission electron spectroscopy to confirm the phase purity. The thin-films also exhibit decent photoconductivity which demonstrate its potential as a non-toxic, air-stable absorber materials for PV.