Advancements in eco-friendly lead-free perovskite/Sb2Se3 tandem solar cells: TCAD simulations

Abstract

In light of the urgent need for sustainable energy solutions, this research addresses the critical environmental concerns of traditional lead-based perovskite materials. This paper explores advancements in an eco-friendly tandem solar cell (TSC) that incorporates both lead-free wide bandgap perovskite and narrow bandgap antimony selenide (Sb₂Se₃), focusing on optimization strategies utilizing TCAD numerical simulations. The study begins with the calibration of experimental standalone solar cells based on wide bandgap lead-free perovskite (1.62 eV) with a p-i-n heterostructure and narrow bandgap Sb₂Se₃ (1.2 eV) with an n-i-p configuration. The research then transitions to evaluating the lead-free perovskite/Sb₂Se₃ system in a four-terminal (4-T) tandem, followed by optimization of the top cell to an n-i-p heterostructure for compatibility with a two-terminal (2-T) structure. Key optimization areas include replacing the organic hole transport layer (HTL) with other inorganic candidates, conduction band offsets (CBOs), and absorber thicknesses. Through these optimizations, the 2-T tandem design achieves a significant improvement, with a simulated PCE reaching 30.96 %. Numerical simulations using TCAD tools are employed to predict performance and guide experimental modifications. This research integrates material science and advanced TCAD simulations to optimize TSC performance with a focus on eco-friendly materials for environmental sustainability.