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

Antimony sulfide (Sb 2 S 3 ) 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 (Na 2 SO 3 ) using a programmable peristaltic pump. This strategy achieved precise control over the release kinetics of S 2– and Sb 3+, yielding denser Sb 2 S 3 films with enhanced crystallinity, reduced oxygen incorporation, and lower defect density. In full-inorganic FTO/TiO 2 /CdS/Sb 2 S 3 /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 Sb 2 S 3 solar cells using graphite electrodes. Notably, all functional layers were synthesized via the inherently safe and tunable CBD process. This study elucidates Sb 2 S 3 deposition kinetics and proposes a dynamic injection strategy with potential applications in doping control and bandgap engineering for broader chalcogenide materials.