Numerical simulation study of lead-free perovskite solar cells using bifunctional molecule CBz-PAI as interfacial layer

Abstract

The urgent demand for sustainable energy solutions has accelerated research into perovskite solar cells (PSCs), which are emerging as a promising alternative to conventional photovoltaics due to their high efficiency and cost-effectiveness. However, the widespread use of lead in most efficient PSCs presents serious environmental and health concerns, severely limiting their potential for large-scale industrial application. To address these challenges, this study proposes a lead-free tin-based PSC incorporating a bifunctional carbazole-based derivative, CBz-PAI, as an interfacial layer. The multifunctional properties of CBz-PAI enable it to effectively optimize interfacial energy level alignment, passivate defects, and improve charge transport. These effects were systematically analyzed using SCAPS-1D simulations, with additional evaluation of the device's thermal stability and performance under varying temperatures. The results demonstrate that the introduction of CBz-PAI significantly enhances device efficiency by reducing interfacial charge recombination and improving solar energy harvesting, achieving an impressive power conversion efficiency (PCE) of 29.33 %. Furthermore, the structure demonstrates excellent thermal stability, thus underscoring the viability of tin-based PSC as a lead-free alternative. This work underscores the potential of carbazole derivatives in advancing environmentally friendly PSC technologies and provides a foundation for future experimental and theoretical research into high-performance lead-free photovoltaics.