Proceedings of MATSUS Spring 2024 Conference (MATSUS24)
DOI: https://doi.org/10.29363/nanoge.matsus.2024.284
Publication date: 18th December 2023
Recent advancements in halide perovskite photovoltaics have brought power conversion efficiencies to levels suitable for commercial use. Despite these advances, the durability of these devices is a major challenge that needs further improvement. A notable development in this area is the use of Ruddlesden-Popper (RP) two-dimensional (2D) perovskite layers on top of traditional three-dimensional (3D) perovskite active layers, enhancing the stability of perovskite solar cells (PSCs) [1-2]. While there have been several reports of efficient and stable PSCs using 2D/3D heterojunctions [3-4], the detailed interactions at the 2D/3D interface are not fully understood. Understanding the relationship between the atomic structure at this interface and electron behavior is essential to comprehend the effectiveness of these methods and to optimize the benefits of interface engineering. In this work, we used density-functional theory (DFT) calculations to explore how the atomic arrangement at interfaces influences the characteristics of 2D/3D halide perovskite heterojunctions. Our findings indicate that the thermodynamic stability and band alignment of these heterojunctions are significantly influenced by the arrangement of Cs/PEA cations at the interfaces.