Enhancing Photovoltaic Performance of Bi-Doped Perovskite Solar Cells with Novel Double Electron Transport Layer: Achieving High Open-Circuit Voltage and Efficiency

Abstract

Perovskite solar cells using pristine and 6% Bi-doped MAPbI2Br perovskite layers are deposited using a spin coating route. XRD analysis reveals that the structure of MAPbI2Br is cubic and the grown films are integrating large grains with low micro-strain. UV-visible spectra of the MAPbI2Br perovskite solar cell and the 6% Bi-doped MAPbI2Br perovskite solar cell show a narrower bandgap (Eg) and higher refractive index. The characteristics of the ETL directly affect the photovoltaic performance of Bi-MAPbI2Br perovskite material. The present report aims to propose a new double electron transport layer composed of TiO2 and Al-SnO2 for MAPbI2Br-based PSCs. In the experimental approach, we reached a high open circuit voltage value of 1.07V, while achieving remarkable power conversion efficiencies of 10.39 %. Notably, this is consistent with the highest Voc achieved so far for Bi-MAPbI2Br-based PSCs with an inorganic electron transport layer (Al-SnO2). The results from this study underscore the importance of the conduction band alignment of MAPbI2Br with the conduction band of Al-SnO2 to enhance electron flow and minimize recombination. This alignment leads to increased Voc and total PCE for PSCs.