Low-resistive tin (II) sulfide thin films for nontoxic and low-cost solar cell devices

Tin (II) sulfide (SnS) thin films have been developed on highly conductive indium doped tin oxide (ITO) substrates by using thermal evaporation technique at optimized deposition conditions. Here, SnS films were deposited at a substrate temperature of 300 °C by maintaining 14 cm distance between source to substrates with a rate of deposition of 1-2 nms−1 and film thickness of 500 nm. Then, the crystal structure, morphology, electrical, and optical properties along with chemical composition of SnS films have been investigated and discussed in view of their potential applications in photovoltaic technology. The obtained results reveal that SnS films grown on ITO substrates have (111) as preferential orientation crystals with different sizes. These films are highly rough-in surface morphology, and exhibited very low-electrical resistivity in the order of 10−3 Ωcm. These films also exhibited direct optical band gap and transmittance of about 60%. From these investigations we emphasized that SnS films deposited on ITO substrates could be adopted as an absorber layer for the development of solar cell devices or active component for other multifunctional devices.