Dynamic Injection-Regulated Growth Kinetics of Sb ₂ S ₃ Films for High-Efficiency Solar Cells

Antimony sulfide (Sb2S3) is a promising solar abosrber due to its excellent optoelectronic properties. However, efficiency improvements are hindered by a limited understanding of complex reaction mechanisms in solution-based deposition, particularly the unclear dynamic evolution of the ionic environment during sulfur-source decomposition. To address this, we modified conventional chemical bath deposition (CBD) by dynamically injecting sodium sulfite (Na2SO3) using a programmable peristaltic pump. This strategy achieved precise control over the release kinetics of S2– and Sb3+, yielding denser Sb2S3 films with enhanced crystallinity, reduced oxygen incorporation, and lower defect density. In full-inorganic FTO/TiO2/CdS/Sb2S3/PbS/graphite devices, the optimized dynamic injection approach delivered a power conversion efficiency (PCE) of 7.60%, surpassing the conventional CBD method (6.88%) and representing the highest reported value for Sb2S3 solar cells using graphite electrodes. Notably, all functional layers were synthesized via the inherently safe and tunable CBD process. This study elucidates Sb2S3 deposition kinetics and proposes a dynamic injection strategy with potential applications in doping control and bandgap engineering for broader chalcogenide materials.