Orientation control of close-spaced sublimation processed Sb2S3 thin films for efficient and stable planar solar cells

Sb2S3 has attracted tremendous attention for sustainable thin film photovoltaics in recent years due to its excellent structural and optoelectronic properties. To employ this quasi-1D material for solar cells, the orientation control of Sb2S3 films is very important. In this Letter, we employ the scalable close-spaced sublimation (CSS) method to deposit favorable [hkl, l ≠ 0]-orientated and compact Sb2S3 films for efficient and stable solar cells. The insights into the growth mechanisms of Sb2S3 films are provided. The deposition rate is one of the key parameters in controlling the film orientation and morphology. Based on the desired film properties, which afford efficient charge transport and suppressed carrier recombination, the best-performing planar Sb2S3 solar cell yields an impressive power conversion efficiency of 4.09% without any modification strategies, which is the highest value for CSS-deposited Sb2S3 system. Moreover, the excellent indoor performance of 11.26% under 1000 lux light-emitting-diode illumination for Sb2S3 devices demonstrates the great potential of using Sb2S3 indoor photovoltaics to power the Internet of Things electronics.