Solution-Processable Cu(3)BiS(3) Thin Films: Growth Process Insights and Increased Charge Generation Properties by Interface Modification

[Image: see text] Cu(3)BiS(3) thin films are fabricated via spin coating of precursor solutions containing copper and bismuth xanthates onto planar glass substrates or mesoporous metal oxide scaffolds followed by annealing at 300 °C to convert the metal xanthates into copper bismuth sulfide. Detailed insights into the film formation are gained from time-resolved simultaneous small and wide angle X-ray scattering measurements. The Cu(3)BiS(3) films show a high absorption coefficient and a band gap of 1.55 eV, which makes them attractive for application in photovoltaic devices. Transient absorption spectroscopic measurements reveal that charge generation yields in mesoporous TiO(2)/Cu(3)BiS(3) heterojunctions can be significantly improved by the introduction of an In(2)S(3) interlayer, and long-lived charge carriers (t(50%) of 10 μs) are found.