Controllable vapor transport deposition of efficient Sb2(S,Se)3 solar cells via adjusting evaporation source area

Abstract

The vapor transport deposition (VTD) processing is one of the most promising techniques to fabricate quasi-one-dimensional antimony selenosulfide (Sb2(S,Se)3) photovoltaic materials with micrometer-scale grains and preferred crystal orientations. However, current researches rarely involve the effect of evaporation source on the film growth by VTD. Herein, we adopt Sb2(S,Se)3 tablets as evaporation sources to develop Sb2(S,Se)3 solar cells for the first time. We find that increasing the evaporation source area can effectively improve the deposition rate of Sb2(S,Se)3 films, leading to an enhancement of the (221) preferred orientation and columnar large grains of the absorber layers, further improves the device photovoltaic performance. With fine-tuning of the evaporation source area, the optimized Sb2(S,Se)3 solar cells show a high efficiency up to 7.6%. This study proposes a unique strategy to improving the quality of low-dimensional materials and a deeper understanding of the growth mechanism via vacuum methods.