Lead-free Cs2TiBr6 perovskite solar cells achieving high power conversion efficiency through device simulation

Abstract

Recently, lead-based perovskite solar cells (PSCs) have gained significant attention in the photovoltaic industry due to their remarkable properties such as high bandgap and high absorption coefficient. However, challenges such as toxicity, instability, and short shelf life limit the use of inorganic-organic lead-based PSCs. To address these issues, researchers introduced eco-friendly, lead-free, and stable cesium titanium (Cs₂TiBr₆) single-halide absorber material. The aim of this work is to perform the numerical modelling and simulation of FTO/SnO₂/Cs₂TiBr₆/CBTS/Au structure incorporating interfacial defect layers (IDL) using SCAPS-1D to examine and study its characteristics properties about various photovoltaic (PV) parameters such as light-absorbing layer thickness, charge transport layer thickness, doping, defect density, operating temperature, and quantum efficiency (QE). After evaluating these parameters, the proposed single-halide Cs₂TiBr₆-based structure shows superior performance as compared to previously reported experimental and simulation-based Cs₂TiBr₆ perovskite structures. The results show a maximum power conversion efficiency (PCE) of 24.24 %, with a fill factor (FF) of 88.9 %, an open-circuit voltage (V_OC) of 1.31 V, and a short-circuit current density (J_SC) of 20.76 mA/cm². This work encourages researchers to develop low-toxic, and stable PSCs for the future solar cell industry.