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

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.