Dynamic Injection-Regulated Growth Kinetics of Sb2S3 Films for High-Efficiency Solar Cells

Abstract

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 S^2– 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.