Optimizing CuBi₂O₄ Solar Cells with PCBM Electron Transport Layer: A Comprehensive Simulation Study Achieving 32.16% Efficiency

This work presents the design, simulation, and evaluation of photovoltaic (PV) parameters for a solar cell structure (Au/CuBi₂O₄/PCBM/ITO/Ag) with copper bismuth oxide (CuBi₂O₄) as the absorber layer and PCBM as the electron transport layer (ETL), using SCAPS-1D software. The PV parameters of the cell were evaluated with varying thicknesses of CuBi₂O₄ and PCBM layers from 0.1 µm to 2 µm, and 100 nm to 500 nm, respectively. The effects of the variations in doping concentrations, the defect density of the absorber and ETL (10¹²–10²⁰ cm⁻³), series resistance (R_s), shunt resistance (R_sh), the band gap of the absorber layer (1.3–1.8 eV), and operating temperature on the PV parameters were also evaluated. The optimized cell exhibited photoconversion efficiency (PCE) of 32.16% with open-circuit voltage (V_oc) of 1.32 V, short-circuit current density (J_sc) of 27.46 mA/cm², and fill factor (FF) of 88.69% with an optimum absorber layer thickness of 1 µm and ETL of 200 nm.