Formation of Cu3BiS3 thin films via sulfurization of Bi-Cu metal precursors

► Sulfurization of Cu-Bi thin films with elemental sulfur vapor. ► Effect of heating rate and temperature on structure and morphology. ► High heating rates are detrimental at temperatures higher than ~ 300 °C. ► Contrary to literature on H2S sulfurization, no Bi depletion was observed. ► Band-gap energy suitable for photovoltaic use, but efficiency needs improvement.