Interface Engineering: A Step Towards Device Integration of Chalcogenide Perovskites

Abstract:Chalcogenide semiconductors have played a crucial role in a wide range of applications, including optoelectronics, photovoltaics, sensing, and more. Chalcogenide perovskites have recently emerged as a new and promising addition to this family, offering enhanced stability along with promising properties. The improved stability is achieved at the expense of rigorous synthesis conditions, often requiring high temperatures and sulfur-rich environments. Such aggressive conditions are highly detrimental to most conductive back contacts, thereby severely limiting device integration. In this work, we address this challenge by introducing an ultrathin Al2O3 layer as a protective barrier. Al2O3 film of a few nanometers was deposited via atomic layer deposition onto a molybdenum substrate, forming a robust interfacial layer that prevents substrate degradation. This interfacial engineering has enabled, for the first time, the deposition of phase-pure BaZrS3 thin films on conductive substrates without degradation. These results represent a critical step towards the realization of functional chalcogenide perovskite devices.