Visible-light photoelectric response in semiconducting quaternary oxysulfide FeOCuS with anti-PbO-type structure.

A novel quaternary oxysulfide, FeOCuS has been successfully synthesized with a tetragonal anti-PbO-type structure and a visible-light bandgap of about 1.37 eV. Driven by only a 0.4 V bias voltage under simulated AM 1.5 G illumination, a high photocurrent density of 3.89 mA cm-2 has been achieved, revealing the potential optoelectronic applications.