Design and simulation of 2D Ruddlesden-Popper perovskite solar cells under LED illumination: Role of ETL and front contact band alignment

This paper focuses on the design and simulation of 2D Ruddlesden-Popper halide perovskite (RPHP) solar cells, emphasizing their optimization for indoor LED illumination conditions. The design process begins with the validation of physical models within the SCAPS device simulator, accomplished through careful calibration against experimental (MAMP)MAn_ 1PbnI3n+1 RPHP cell data. Subsequently, different values of (with n = 1, 2, 3, and 4) are explored to study the impact of different band gap energies, aiming to identify the most suitable option for optimal efficiency across diverse LED color temperatures. By addressing both material-specific considerations and device architecture optimization, this study aims to establish a comprehensive framework for designing RPHP solar cells tailored for white LED illumination. Additionally, the simulation reveals that optimizing the electron affinity of the Electron Transport Layer (ETL) significantly impacts device performance, with efficiencies exceeding 25 %. Furthermore, the study discusses emerging trends such as ETL-free structures, which aim to address interface defects and enhance device performance. In addition, we analyze the impact of bulk trap density and thickness of the 2-D perovskite absorber on efficiency limitations. With an absorber thickness set at 800 nm, a marginal decrease in PCE is observed, for the ETL-free solar cell, from around 34 % to 32 % as the trap density ranges from 1011 to 1014 cm- 3. In contrast, for the ETL-based structure with the same variations, PCE experiences a substantial decline, dropping from approximately 47 % to 37 %. While the ETL-free structure may exhibit a lower PCE compared to the ETL-based cell, its capacity to endure fluctuations in trap density offers a notable advantage. These efforts underscore the potential of 2D RPHP photovoltaic cells for indoor applications, presenting a pathway towards efficient, stable, and cost-effective photovoltaic technology suited for diverse lighting environments.