Solvent Annealing Enabling Reconstruction of Cadmium Sulfide Film for Improved Heterojunction Quality and Photovoltaic Performance of Antimony Selenosulfide Solar Cells

Abstract Antimony selenosulfide, Sb₂(S,Se)₃, has been considered as new‐generation light‐harvesting material for high‐efficiency photovoltaic applications due to its adjustable bandgap, high absorption coefficient, and excellent stability. In terms of device operation, the electron transfer from the electron transporting layer to Sb₂(S,Se)₃ layer plays a critical role in improving the photovoltaic energy conversion efficiency of solar devices. Intricately manipulating the surface and interface properties has been a great challenge in solar cell fabrications. Herein, an effective approach toward the reconstruction of the CdS interfacial layer, and the following Sb₂(S,Se)₃ absorber film by utilizing polar ethylenediamine (EDA) solvent annealing at room temperature is developed. It is found that the presence of nitrogen‐containing functional groups of EDA on the CdS surface not only promotes the grain growth and crystallization of CdS, but also induces optimized deposition of Sb₂(S,Se)₃ films in terms of interfacial contact and defect formation. Finally, the Sb₂(S,Se)₃ solar cell based on EDA–CdS achieves a top efficiency of 10.10%. This study provides an efficient method and a new understanding of chemically healing inorganic thin films.