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.