Numerical simulation of a lead-free double perovskite heterostructure device with different charge transport layers

Abstract

Perovskite solar cells can convert more than 25% of insolation which is comparable to silicon solar cells. However, they are yet to be deployed on a large scale because they rely on poisonous lead and unstable. Researchers are now investigating lead-free double perovskites, which have good optoelectronic properties and are safe for the environment. Lanthanum nickel manganese oxide (LNMO) stands out due to its adjustable band gap and chemical stablity. This makes it an excellent contender for long-lasting photovoltaic uses. In this work, we employ SCAPS-1D device simulations to systematically optimize the photovoltaic performance of LNMO (Lanthanum Nickel Manganese Oxide) based heterostructure cells through band-gap engineering of the absorber layer from 1.0 eV up to 2.2 eV, screening of six electron-transport layers (TiO₂, PCBM, C₆₀, IGZO, WS₂, CeO₂) against twelve hole-transport layers ( PEDOT:PSS, CuSCN, Spiro-OMeTAD, etc.) to identify the best charge-extraction interfaces, and thickness variation studies for the optimal ETL/HTL pairing. Our results reveal that WS₂ combined with PEDOT: PSS yielded a power-conversion efficiency (PCE) of 23.7 %, outperforming conventional TiO₂-based architectures. Further optimization of the LNMO absorber thickness shows a maximum PCE of 27.18 % at 1 450 nm, with corresponding open-circuit voltage (Voc) of 1.261 V, short-circuit current density (Jsc) of 27.62 mA cm⁻², and fill factor (FF) of 78.03 %. These findings deliver concrete design guidelines with optimal band-gap window (1.50–1.625 eV), preferred ETL/HTL combination (WS₂/PEDOT: PSS), and absorber thickness (~1.45 µm) for realizing high-efficiency, stable, lead-free Perovskite Solar Cells.