Advanced Optimization of Bandgap Grading Techniques in CsPbBr3-xIx Perovskite Solar Cells for Achieving Remarkable 30.96% Efficiency

The solar cells efficiency has been enhanced over the past few decades using a variety of theoretical and scientific approaches. This study uses grading approaches to increase PV cell efficiency. Parabolic and linear grading profiles are applied to simulate the device structure. By adjusting the material's energy band gap, grading of the absorber layer maximizes the cell's capacity to absorb high-wavelength photons, hence lowering transmission and recombination losses. To achieve the maximum efficiency, we optimize the absorber layer thickness, temperature, series and shunt resistance, and various defect densities. In this study, we focus on a linear and parabolic grading band gap technique for our solar device arrangement Au/Spiro-OMeTAD/CsPbBr3-xIx/rGO/TiO2/FTO. The reduced graphene oxide layer (rGO) acts as an intermediary layer between the CsPbBr3-xIx perovskite(PVSK) and the ETL layer, and spiro-OMeTAD as the HTL and TiO2 as the ETL. The graded bandgap perovskite layer is CsPbBr3-xIx. More importantly for improving solar cell efficiency, Without really collecting the moving charges rGO may also serve as a powerful intermediary to enhance the charge injection from the CsPbBr3-xIx absorber layer to the TiO2 (ETL) layer, this reveals to be of greater significance for boosting the effectiveness of solar cells. With an amazing result of 30.96% for parabolic grading, our simulations demonstrate a considerable improvement in Power conversion efficiency (PCE), which is 7.8% higher than PCE from linear grading of 28.72%. Additional significant measures that demonstrate outstanding results include J(SC) 22.786 mA.cm(-2), V-OC 1.5383 V and FF 88.34%. These outcomes indicate how our approach improves the performance and efficiency of the solar cell.