Vapor Transport Deposition of Highly Efficient Sb2(S,Se)3 Solar Cells via Controllable Orientation Growth

The vapor transport deposition of quasi‐one‐dimensional antimony selenosulfide (Sb2(S,Se)3) has recently attracted increasing research interest for the inexpensive, high‐throughput production of thin film photovoltaic devices. Further improvements in Sb2(S,Se)3 solar cell performance urgently require the identification of processing strategies to control the orientation, however the growth mechanism of high quality absorbers is still not completely clear. Herein, a facile and general vapor transport deposition approach to precisely control the growth of large‐grained dense Sb2(S,Se)3 films with good crystallization and preferred orientation via the source vapor speed is utilized. It is found that defect activation energy rather than the defect concentration plays a decisive role in the Sb2(S,Se)3 photovoltaic performance. Admittance spectroscopy analysis is used to obtain efficient Sb2(S,Se)3 solar cells. By employing dual‐source coordinations to optimize the absorber layer a power conversion efficiency of 8.17% is obtained which is the highest efficiency for Sb2(S,Se)3 solar cells fabricated by vapor transport technology. This study suggests that there are other opportunities for gaining deeper a understanding of the defect physics and carrier recombination mechanisms in other highly oriented low‐dimensional materials to achieve improved device performance.