Enhanced Efficiency and Stability in Sb2S3 Seed Layer Buffered Sb2Se3 Solar Cells

Abstract Antimony selenide (Sb 2 Se 3 ) has excellent directional optical and electronic behaviors due to its quasi‐1D nanoribbons structure. The photovoltaic performance of Sb 2 Se 3 solar cells largely depends on the orientation of the nanoribbons. It is desired to grow these Sb 2 Se 3 ribbons normal to the substrate to enhance photoexcited carrier transport. Therefore, it is necessary to develop a strategy for the vertical growth of Sb 2 Se 3 nanoribbons to achieve high‐efficiency solar cells. Since antimony sulfide (Sb 2 S 3 ) and Sb 2 Se 3 are from the same space group (Pbnm) and have the same crystal structure, herein an ultrathin layer (≈20 nm) of Sb 2 S 3 has been used to assist the vertical growth of Sb 2 Se 3 nanoribbons to improve the overall efficiency of Sb 2 Se 3 solar cell. The Sb 2 S 3 thin layer deposited by the hydrothermal process helps the Sb 2 Se 3 ribbons grow normal to the substrate and increases the efficiency from 5.65% to 7.44% through the improvement of all solar cell parameters. This work is expected to open a new direction to tailor the Sb 2 Se 3 grain growth and further develop the Sb 2 Se 3 solar cell in the future.