Cu2SnS3 based photovoltaic structure with improved open circuit voltage for air stable self-driven enhanced NIR photodetection

Abstract

Copper tin sulfide (Cu2SnS3) is an environmentally benign and economical semiconductor comprising earth-abundant, non-toxic elements with flexible optoelectronic properties for photovoltaic energy conversion and photodetection. The optimization of sulfurization temperature resulted in significant improvement in structure, morphology, elemental composition, optical and electrical properties. A substantial advancement in photovoltaic performance was achieved by integrating a thin layer of SnS and the same enhancement theoretically predicted using SCAPS-1D simulation. Photovoltaic structure with optimized monoclinic Cu2SnS3 as an absorber layer and thin SnS layer (Glass/FTO/CdS/SnS/Cu2SnS3/Ag) resulted in photovoltaic parameters: Voc = 415 mV, Jsc = 17.2 mA.cm−2, and PCE = 2.12 %. We demonstrate the first self-powered SnS/Cu2SnS3 based photodetector which delivers high detectivity of 1.41 × 1011 Jones under the illumination of an 840 nm laser with rapid rise and decay time of 10.2 and 10.1 ms, respectively. Economic and environmentally benign Cu2SnS3 thin films based photovoltaic structures will be beneficial for harvesting sustainable energy and paving a strong platform for self-powered, air-stable, and spectral selective photodetection.