Strontium encapsulated molybdenum diselenide as an enhanced electron transport layer for high efficiency perovskite solar cells

• Hydrothermal synthesis used for pristine and Sr@MoSe₂ ETL synthesis. • Sr@MoSe₂ achieves J sc of 13.73 mA/cm², V oc of 1.04 V, and FF of 82% and PCE of 10.12%. • ETL optimization via Sr doping boosts stability and photovoltaic performance. . Perovskite solar cells (PSCs) have emerged as a transformative technology in photovoltaics due to their high absorption coefficient and potential for low-cost, high-efficiency solar energy conversion. Optimizing the electron transport layer (ETL) remains a critical challenge, as it significantly influences charge carrier dynamics and overall device performance. This study explores strontium (Sr) doped hydrothermally synthesized molybdenum diselenide (MoSe₂) as ETL to enhance the power conversation efficiency (PCE) of the PSCs. The encapsulation of Sr within MoSe₂ (Sr@MoSe₂) demonstrates a notable enhancement in photovoltaic parameters, achieving a short-circuit current density ( J sc) of 13.73 mA/cm², an open-circuit voltage ( V oc) of 1.04 V, a fill factor (FF) of 82%, and a power conversion efficiency (PCE) of 10.12%, compared to pristine MoSe₂ ( J sc = 11.05 mA/cm², V oc = 1.03 V, FF = 70%, PCE = 7.97%). Transient photovoltage and impedance spectroscopy analysis confirm that Sr modification facilitates improved charge extraction and reduces recombination losses at the ETL perovskite interface. These results underscore the effectiveness of Sr incorporation in enhancing both the efficiency and operational stability of perovskite solar cells. This work not only provides a promising strategy for ETL optimization but also opens avenues for future research into tailored material engineering for next-generation photovoltaic devices. .