Exploring 32 % efficiency of eco-friendly kusachiite-based solar cells: A numerical study

Recently, solar cells have appeared as a promising solution to meet the increasing energy demand. However, their large-scale commercial use is limited by issues such as toxicity (Cd, Pb, etc), high manufacturing costs, lower stability, and low efficiency. In this perspective, kusachiite solar cells (KSCs) are environmentally friendly, long-term stable, and easy to manufacture. Thus, in this work, kusachiite (CuBi₂O₄) is used as an absorber layer, with NiO and SrTiO₃ serving as the hole transport material (HTM) and an electron transport layer (ETL), respectively. The KSCs, with a structure of FTO/SrTiO₃/CuBi₂O₄/NiO/Au, are numerically simulated. Maximum power conversion efficiency is achieved by optimizing several photovoltaic parameters, such as the thickness and doping density of the ETL, absorber, and HTM. The optimized thicknesses for the HTL, absorber layer, and ETL are 1.5 μm, 2.28 μm, and 0.02 μm, respectively. The designed KSCs exhibit an efficiency eta (η) of 31.89 %, an open-circuit voltage (V_oc) of 1.31 V, a short-circuit current (J_sc) of 28.58 mA/cm², and a fill factor (FF) of 84.99 %.