Effect of PEDOT:PSS optical properties at the frontal interface on electrical performance in MAPbI3 perovskite solar cells

Abstract

This article presents a thorough analysis of perovskite-based solar cells (PSCs) by integrating optical and electrical simulations. The investigation includes simulations of both optical and electrical characteristics of a PSC configuration featuring a MAPbI3 active layer, PEDOT:PSS as the hole transport layer (HTL) at the front interface, and PC60BM and BCP at the back interface. Optical simulations utilized the optical admittance method and transfer matrix method, with optical constants such as refractive index (n) and extinction coefficient (k) derived from transmittance measurements of the fabricated layers. Electrical simulations were performed using the Solar Cell Capacitance Simulator One Dimension (SCAPS-1D) software, focusing on the influence of optical losses due to total reflection at the interfaces. Discrepancies in short-circuit current density (Jsc) of about 3 mA/cm2 were revealed between simulations employing optical constants of PEDOT:PSS determined via Tauc-Lorentz-Drude (TLD) and B-spline (BSPL) model fitting to transmittance data. Optimal parameters for achieving the highest power conversion efficiency (PCE) were identified, with PEDOT:PSS layer thicknesses below 15 nm and MAPbI3 layer thicknesses above 305 nm. The maximum efficiency ranged between 10.42 % and 12.10 %, close to conventional experimental perovskite solar cells with the same structure. A key observation highlighted the overestimation of Jsc and PCE when simulated total reflectance was neglected in electrical simulations. These findings underscore the significance of incorporating optical data into electrical simulations, offering critical insights for PSC optimization. Overall, this study enhances our understanding of the intricate relationship between optical and electrical parameters, essential for advancing high-performance PSC development.