Bulk Defect Passivation for Full‐Inorganic Sb2S3 Solar Cells by Sulfur‐Atmosphere Recrystallization Process

Abstract

Antimony sulfide (Sb2S3) solar cells have attracted extensive attention in silicon‐based tandem solar cells. The performance of Sb2S3 devices fabricated by the vacuum method is limited by sulfur vacancies (VS) and surface oxide defects during high‐temperature processes. Herein, amorphous Sb2S3 film based on low‐temperature rapid thermal evaporation (RTE) technique is fabricated to overcome S loss. Moreover, a sulfur‐atmosphere recrystallization strategy is further developed to obtain high‐quality absorbers from the amorphous film. The element content of Sb2S3 film is completely in accord with the stoichiometric ratio (2:3), and the surface oxides are effectively suppressed, enhancing VOC and fill factor. Compared to the control directly crystallized film, the defect concentrations of the S‐recrystallized Sb2S3 film are reduced by 61%, exhibiting better uniformity and higher PN junction quality. Ultimately, the full‐inorganic Sb2S3 solar cells (FTO/TiO2/Sb2S3/Au) achieve an efficiency of 6.25%. The S‐atmosphere recrystallization process can effectively passivate bulk defects (VS and Sb2O3) and suppress recombination to improve device performance, which will provide new prospects for vacuum method‐based Sb2S3 thin film solar cells.