Efficiency and Stability Optimization of Methyl Ammonium Lead Halide Perovskite: A Future Photovoltaic Solar Power for Mass Production

Despite the rapid progress achieved in stability optimization of methylammonium lead iodide (CH₃NH₃PbI₃, MAPbI₃)–based perovskite solar cells (PSCs), further enhancement of device efficiency and operational stability remains a critical challenge, particularly through the optimization of charge transport layers. In this work, Ag–In co-doped SnO₂ thin films were synthesized via a cost-effective spray pyrolysis deposition technique and systematically investigated as electron transport layers (ETLs) for planar MAPbI₃ PSCs. The influence of silver doping concentration on the structural, optical, and electrical properties of SnO₂ was experimentally examined using Hall effect and UV–Vis spectroscopy measurements. The optimized SnO₂:Ag–In film, containing 3% Ag and 2% In, exhibited a low sheet resistance of 14.2 Ω sq⁻¹, high average optical transmittance of 92.39% in the visible range, and an enhanced optoelectronic figure of merit, indicating an excellent balance between conductivity and transparency.To establish a direct correlation between ETL material properties and device performance, experimentally extracted parameters were incorporated into SCAPS-1D numerical simulations. The optimized device architecture (FTO/Ag–In:SnO₂/MAPbI₃/Cu₂O/Au) achieved a remarkable power conversion efficiency of 31.82%, with an open-circuit voltage of 1.2868 V, a short-circuit current density of 27.42 mA cm⁻², and a fill factor of 90.18%. A comprehensive parametric analysis was further conducted to evaluate the effects of absorber layer thickness, acceptor doping concentration, and defect density on device performance, leading to the identification of optimal design conditions for maximum efficiency. The results reveal that reduced defect density, optimized absorber thickness, and appropriate doping levels significantly suppress recombination losses and enhance charge extraction. Overall, this integrated experimental–simulation study demonstrates that Ag–In co-doped SnO₂ is a highly promising ETL for next-generation high-efficiency perovskite solar cells. The findings provide valuable insights into the rational design and optimization of charge transport layers, offering a viable pathway toward improved performance and stability in lead-based PSC technologies.