Effect of Layer Thickness and Recombination on Charge Transport in 1D Perovskite Solar Cell Models

Perovskite solar cells (PSCs) have demonstrated remarkable efficiency gains over the past decade. However, their performance remains limited by instability issues arising from environmental factors such as humidity, illumination, and temperature, which affect the charge transport processes within the device. Modelling PSCs is particularly challenging due to the complex and dynamic nature of their physical behaviour, requiring detailed consideration of multiple interdependent parameters. This study focuses on modelling the blend-phase layer of an n-i-p structured perovskite solar cell using a one-dimensional drift-diffusion approach which provides a more physically accurate representation of charge carrier dynamics. The coupled equations are solved numerically using the Method of Lines (MOL) technique, which enables efficient temporal integration of spatially discretized equations. Key parameters such as active layer thickness and the bimolecular recombination coefficient are varied to assess their influence on cell performance. Simulation results indicate that the highest observed efficiency is achieved at a perovskite layer thickness of 500 nm with a recombination coefficient of b 1 =1× 10 −10 m 3 ⋅ s −1 .