Computational Optimization and Parameter Analysis of Perovskite–Silicon Tandem Solar Cells Using SCAPS-1D

Abstract

The performance of monolithic perovskite/silicon tandem solar cells is strongly influenced by the optical and electrical properties of their constituent layers. In this study, a numerical investigation of a monolithic perovskite/silicon tandem architecture was carried out using SCAPS-1D under standard AM1.5G illumination. The proposed device consists of an FTO/ZnMgO/FA₀.₈₅Cs₀.₁₅Pb(I₀.₆Br₀.₄)₃/NiCo₂O₄ widebandgap perovskite top sub cell coupled with an ITO/amorphous-silicon/crystalline-silicon heterojunction bottom sub cell. The influence of layer thickness on the photovoltaic response was systematically evaluated by analysing the open-circuit voltage (Vₒc), short-circuit current density (Jsc), fill factor (FF), and power conversion efficiency (PCE). ZnMgO and NiCo₂O₄ thicknesses were varied from 10 to 50 nm, while the crystalline-silicon absorber thickness was varied from 50 to 250 nm. Increasing ZnMgO thickness resulted in a gradual PCE improvement from approximately 4.05% to 4.23%, while NiCo₂O₄ produced a comparatively smaller variation. In contrast, silicon thickness had the strongest influence, increasing Jsc from 4.71 to 14.68 mA cm⁻² and FF from 79.94% to 82.92%, with the calculated PCE increasing from 2.96% to 9.34%; Vₒc decreased from approximately 0.79 to 0.77 V. The results demonstrate the competing effects of enhanced optical absorption, carrier extraction, and bulk recombination and provide useful guidelines for thickness optimization of perovskite/silicon tandem structures.