Cu2SnS3 solar cells fabricated by chemical bath deposition-annealing of SnS/Cu stacked layers

In present study, monoclinic Cu2SnS3 crystalline thin films have been successfully fabricated for the first time using stacked layer SnS/Cu by a CBD-annealing route. The chemical composition, stack order and effects of annealing temperature on Cu2SnS3 thin films and devices have been studied in detail. SEM, XRD, Raman, EDX and UV-vis analyses indicate that Cu2SnS3 absorber layers fabricated by this CBD-annealing route have good morphology, monoclinic crystal structure, relatively proper elements composition (Cu/Sn=1.68) and band gap (Eg~0.87 eV). Furthermore, the photovoltaic cells based Cu2SnS3 thin films have been prepared using CBD for the first time and the device with the order of Mo/SnS/Cu annealed at 600 °C for 10 min with S powder shows the best performance, nearly 1% efficiency (Voc: 157 mV, Jsc: 19.20 mA cm−2, and FF: 31.9%). Alternative approach to produce low-cost and large-scale solar cells may be provided by this CBD-annealing route without the need for expensive vacuum-based deposition equipment.