Facile surface modification process of Sn-doped In₂O₃ electron transport layer for enhanced perovskite solar cell performance

Perovskite solar cell (PSC) devices have achieved a tremendous amount of attention because of their facile fabrication process, high efficiency, and cost-effectiveness. This research mainly focuses on providing a solvent-based surface modification process of Tin-doped Indium Oxide (Sn-doped In₂O₃; Sn-In₂O₃) based electron transport layer (ETL) for PSC's fabrication. The ETL layer should exhibit good optical transparency and electrical conductivity in planner-structured PSC devices for better performance. Pristine and surface-modified Sn-In₂O₃ thin films-based ETLs were prepared by facile spray pyrolysis technique. A solvent-based surface modification process has been carried out to control the grain boundary effect on the charge transfer process of Sn-In₂O₃ film. The surface modification process's impact on the structural, surface morphology, surface charge state, optical, and electrical properties of Sn-In₂O₃ thin films was used to investigate the power conversion efficiency (PCE) of the developed PSCs. The glancing angle X-ray diffraction (GAXRD), X-ray photoelectron spectroscopy (XPS), Field Emission Scanning Electron Microscopy (FE-SEM), AFM, Ultra-Violet visible and Near Infra-Red (UV–Vis–NIR and Hall measurements confirm the significant variation of Sn-In₂O₃ films based on the surface modification process. A surface-modified Sn-In₂O₃ thin film-based ETL-used PSC device demonstrated a maximum efficiency of 14.3 %, whereas a pristine-based Sn-In₂O₃ thin film showed a maximum efficiency of 7.2 %. The results obtained indicate that surface-modified spray-deposited Sn-In₂O₃ thin film can be a suitable candidate to serve as an ETL for PSC device fabrication.