Enhanced Performance of Perovskite Solar Cells with Tungsten-Doped SnO₂ as an Electron Transport Material

This study focuses on the synthesis and characterization of tungsten (W)-doped SnO₂ as an electron transport material (ETM) for perovskite solar cells (PSC). The aim is to enhance the performance of PSCs by improving the properties of the ETM. The W-doped SnO₂ was synthesized by dissolving SnO₂ and W in deionized water, followed by sonication. The doping was achieved using a spin-coating technique, with subsequent annealing at 350 °C for 20 min. X-ray diffraction analysis revealed characteristic peaks of SnO₂ at 2θ values of 26.53°, 33.82°, 37.67°, 51.59°, and 54.69°, alongside an additional peak at 2θ = 14.46°, indicative of successful tungsten incorporation. Field emission scanning electron microscopy confirmed the formation of a uniform electron transport layer on fluorine-doped tin oxide glass, with a thickness of approximately 44.66 nm. UV–Vis spectroscopy measurements showed that the band gap of W-doped SnO₂ was 4.38 eV. Performance evaluation revealed that the W-doped SnO₂ ETL outperformed the undoped SnO₂ ETL in PSC applications, as evidenced by significant improvements in open-circuit voltage (Voc), fill factor (FF), short-circuit current density (Jsc), and power conversion efficiency. Incorporating W into the SnO₂ ETL led to a marked increase in overall device efficiency, corroborated by a hysteresis curve demonstrating reduced J–V loss. The optimized W-doped SnO₂ ETL-based PSC achieved a notable power conversion efficiency of up to 8.02%, with Voc, Jsc, and FF reaching 0.89 V, 23.65 mA/cm², and 0.45, respectively. This study highlights the significant potential of W-doped SnO₂ as a promising ETM for enhancing the efficiency of PSCs.