Enhancing CaV0.5Fe0.5O3-Based Lead-Free Perovskite Solar Cell Efficiency by over 23% via Transport Layer Engineering.

In response to the rising global energy dilemma and associated environmental concerns, research into creating less hazardous solar technology has exploded. Due to their cost-effective fabrication process and exceptional optoelectronic properties, perovskite-based solar cells have emerged as promising candidates. However, their commercialization faces obstacles, including lead contamination, interface recombination, and instability. This study examines CaV0.5Fe0.5O3 (CVFO) as an alternative to lead-based perovskites, highlighting its improved stability and high efficiency through a series of simulation and modeling results. A record power conversion efficiency (PCE) of 23.28% was achieved (Voc = 1.38 V, Jsc = 19.8 mA/cm2, FF = 85.2%) using a 550 nm thick CaV0.5Fe0.5O3 as an absorber. This was accomplished by optimizing the electron transport layer (ETL: TiO2, 40 nm, 1020 cm-3 doping) and the hole transport layer (HTL: Cu2O, 50 nm, 1020 cm-3 doping). Subsequently, it was established that defects at the ETL/perovskite interface significantly diminish performance relative to defects on the HTL side, and thermal stability assessments verified proper operation up to 350 K. To maintain efficiency, it is necessary to reduce series resistance (Rs < 1 Ω·cm2) and increase shunt resistance (Rsh > 104 Ω·cm2). The findings indicate that CaV0.5Fe0.5O3 serves as a feasible alternative to perovskites and has the potential to enhance the performance of scalable solar cells.