Suppressed Defects and Improved Stability of All‐Inorganic CsSnI3 Films by Solid Additive‐Assisted Chemical Vapor Deposition Process

• DOI: 10.1002/smll.202412824
• Publication Date: 2025-05-05T07:15:26Z
• Authors: Hongyu Li; Chao Ye; Yichen Jin; Lifang Wu; Yanwu Ma; Hongliang Dong; Luis K. Ono; Yabing Qi; Sardor B. Donaev; Lin Jiang; Zhifang Wu; Chang Xue; Shenghao Wang
• Keywords: Oxidizing agent; Deposition

Abstract All‐inorganic Sn‐based halide perovskite CsSnI 3 is a promising candidate for solar cells (PSCs) owing to its narrower bandgap (≈1.3 eV) and lower toxicity as compared with traditional organic–inorganic hybrid Pb‐based counterparts. However, rapidly degrades in ambient air simultaneously generates intrinsic defect states, thus seriously impairing the optoelectronic property of film, well corresponding device performance. Herein, solid additive‐assisted chemical vapor deposition (SACVD) method reported prepare films high quality. Combining theoretical calculations, Fourier transform infrared spectroscopy, temperature‐dependent photoluminescence, scanning Kelvin probe techniques prove that lone electron pairs additive form coordination interactions Sn 2+ , resulting suppression oxidizing 4+ reducing density. This work not only provides new strategy eco‐friendly stability‐improved tin thin PSCs, but also reveals underlying physical properties film upon state modification (i.e., without any organic solvent).