Interface Defect Layer Engineering for Realistic Modeling of 2D/3D Mixed Dimensional Perovskite Solar Cells

This study focuses on a comprehensive investigation into the influence of interface defects on the performance of 2D/3D mixed-dimensional perovskite solar cells (PSCs). To address the limitations of the conventional Interface Defect Density (IDD) model, the Interface Defect Layer (IDL) model has been introduced to more realistically represent the effect of the interface defects and recombination losses. Based on two defect models, a 2D/3D mixed dimensional PSC with a device architecture of FTO/TiO2/MAPbI3/BA2MA2Pb3I10/Spiro-OMeTAD/Au was simulated. 2D/3D and 3D/ETL interfaces were identified as critical interfaces in device performance degradation in using the IDD model-based simulations. Accordingly, thin IDL (IDL1 and IDl2) were placed at these interfaces, and their thickness and defect density were systematically optimized. A thickness of 1 nm and a defect density of 10¹³ cm⁻³ were identified to be the most effective values for suppressing recombination and improving efficiency. The study reveals that IDL1 (3D/ETL interface) has a significant effect on photovoltaic parameters than IDL2 (2D/3D interface). The IDL model device achieved a simulated PCE of 19.25%, Voc of 0.98V Jsc of 24.68 mA/cm2, and FF of 79.83% at the optimal thickness and defect density values.