Suppression of Deep-Level Defects and Interface Modification in Antimony Sulfide Thin-Film Solar Cells Via Solution-Processed Sulfurization

Abstract

Antimony sulfide (Sb₂S₃) has garnered considerable interest in photovoltaic technology due to its excellent optoelectronic properties. However, theoretical calculations have revealed complex defect properties in Sb₂S₃, potentially impacting the power conversion efficiency (PCE). In this study, based on the effect of Sb₂S₃ absorber thickness and annealing temperature on the performance of photovoltaic devices, the absorber surface was treated via solution-processed sulfurization using thioacetamide to replenish missing sulfur elements and mitigate interfacial and deep bulk defects. Additionally, this treatment improved the hydrophilic nature of the absorber layer, facilitating subsequent spin-coating of the hole transport layer. Consequently, the efficiency of the champion device increased from 5.90% to 6.50% under standard sunlight, with open-circuit voltage, short-circuit density, and fill factor values of 695 mV, 17.28 mA/cm², and 54.11%, respectively. Furthermore, owing to the inherent high bandgap of Sb₂S₃ and the bandgap widening upon solution-processed sulfurization effect, the device demonstrated a PCE of 10.17% under 1000 lx room illumination, making it promising for indoor applications in the future development of Sb₂S₃-based solar cells.