Achieving high efficiency of Pb–Sn-based dual cation perovskite solar cells via interfacial charge transport layer: A numerical study

Even though perovskite solar cells (PSCs) are well known for their cost-effectiveness and efficiency, their productivity can be further enhanced through appropriate interfacial recombination dynamics and composition engineering of cation sites. The alleviation of toxicity through suitable alloying, alongside hole transport layer (HTL) optimization, ensures eco-friendly and effectual PSCs. To investigate all the aforesaid strategies in a single solar structure, we undertook a numerical simulation study of the following novel arrangement: FTO/PCBM/FAMAPbSnI₃/rGO/HTL/Au. The numerical assessment meticulously optimized interfacial engineering using reduced graphene oxide (rGO), A-site composition engineering (FA/MA), B-site alloying (Pb–Sn), and HTL optimization (PEDOT:PSS, CdTe, and CFTS) through various layer parameter variations. The alterations in key parameters of the rGO interfacial layer, FAMAPbSnI₃ absorber layer, and various CTLs resulted in divergent performance characteristics among the HTL configurations, with the cadmium telluride (CdTe)-based HTL yielding the highest efficiency of 26.36% at an absorber donor density of 1 × 10¹⁸ cm⁻³. Moreover, a peak efficiency of 26.93% was attained with a 10 nm electron transport layer thickness across the various HTL configurations. This work offers an insightful simulation-based perspective that integrates diverse engineering methodologies within a single device design, aiming to regulate band alignment, recombination rates, and toxicity while preserving the device's productivity.