Regulating Energy Band Alignment via Alkaline Metal Fluoride Assisted Solution Post-Treatment Enabling Sb2(S,Se)3 Solar Cells with 10.7% Efficiency

Continuously boosting the power conversion efficiency (PCE) and delving deeper into its functionalities are essential problems faced by the very new antimony selenosulfide (Sb-2(S,Se)(3)) solar technology. Here, a convenient and effective solution post-treatment (SPT) technique is used to fabricate high-performance Sb-2(S,Se)(3) solar cells, where alkali metal fluorides are applied to improve the quality of Sb-2(S,Se)(3) films in terms of morphology, crystallinity, and conductivity. In particular, this approach is able to manipulate the S/Se gradient in the films and creates favorable energy alignment which facilitates the carrier transport. As a result, the fill factor and short-circuit current density of Sb-2(S,Se)(3) solar cells (Glass/FTO/Zn(O,S)/CdS/Sb-2(S,Se)(3)/Spiro-OMeTAD/Au) based on the SPT strategy are significantly enhanced, achieving a champion efficiency of 10.7%. To date, this conversion efficiency value represents the highest efficiency of all Sb-based solar cells. This study provides an effective post-treatment strategy for improving the quality of Sb-2(S,Se)(3) film which sheds new light on the fabrication of high-efficiency Sb-2(S,Se)(3) solar cells.