Perovskite-Chalcogenide Epitaxial Heterostructures: A Computational Study

The commercialization of perovskite solar cells (PSCs) is still limited by common efficiency loss and long-term stability issues when scaling up solar cells.1 On the other hand, it has been observed that chalcogenides enhance the properties of PSCs when incorporated into transport layers.2 However, despite evidence that such structures enhance charge transport and perovskite growth,3 research on epitaxial heterostructures in these two materials has been limited.4 Recently, a CsPbBr3/PbSe epitaxial nanocrystal was successfully synthesized, confirming its interesting decrease in hot carrier cooling.4 This phenomenon could provide access to high-energy photons, which are usually lost due to thermalization, potentially exceeding the Shockley-Queisser limit.5 My contribution aims to shed light on the physical and chemical mechanisms behind the optoelectronic properties of CsPbBr3/PbSe epitaxial heterostructures. This will be achieved by performing accurate first-principles calculations based on density functional theory and ab initio molecular dynamics, and by analyzing the electronic and structural properties of the system. This study not only aims to characterize the CsPbBr3/PbSe system, but also paves the way for broader research into perovskite-chalcogenide epitaxial heterostructures with different compositions, facilitating the rational design of high-quality interfaces in PSCs in the future.