Novel asphaltene-TiO2 electron transport layers for high-performance perovskite solar cells: synthesis and characterization

Abstract

Perovskite solar cells (PSCs) demonstrate significant potential but require further improvement. This study examines the utilization of asphaltene to modify the electron transport layer (ETL) and enhance the PSC performance. This study involved the fabrication of mesoscopic PSCs using mp-TiO₂ ETLs modified with varying concentrations of asphaltene. The addition of 1 wt% asphaltene resulted in significant increases in the short-circuit current density (J_sc), fill factor (FF), and power conversion efficiency (PCE) compared to devices with unmodified mp-TiO₂. The optimal device achieved a PCE of 8.77%, representing an improvement of 54%. This enhancement is attributed to the improved crystalline structure, reduced charge recombination at the TiO₂/perovskite interface, passivated grain boundaries, and enhanced edge absorption. Notably, the 1 wt% asphaltene modification exhibited superior performance and stability compared to the 3 wt% modification. Modification of the ETL with asphaltene in PSCs has emerged as a promising approach for achieving higher efficiency and stability. The study concluded that 1 wt% was the optimal concentration for this modification.