Enhancing the Efficiency of Au/Spiro-OMeTAD/MAPbI3/ZnO/FTO/Glass Solar Cells: A Numerical Approach

This study presents an advanced numerical investigation of a perovskite solar cell with an Au/Spiro-OMeTAD/MAPbI3/ZnO/FTO/Glass configuration, carried out using the SCAPS-1D simulation software. The main objective was to evaluate the influence of several structural and electrical parameters on the overall behavior of the device, with particular attention given to the thickness of the hole transport layer (HTL), the carrier density, and the hole mobility within this layer. By systematically varying these parameters, the numerical simulation allowed a clear identification of their individual and combined impact on the cell's output characteristics, including open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency. The results reveal that the device's performance is strongly dependent on the HTL thickness as well as on the hole transport properties, reflecting Spiro-OMeTAD's role as a p-type hole transport layer. It was found that a hole transport layer (HTL) thickness of 100 nm, combined with a hole mobility of μh = 1×10⁻⁴ cm²V⁻¹s⁻¹, achieves optimal performance, with a power conversion efficiency of 15.35%. In addition, the optimized structure exhibits a high External Quantum Efficiency (EQE), reaching nearly 90% in the visible light range. These results provide valuable insights for the design and optimization of efficient MAPbI3-based perovskite solar cells.