Physical Vapor Deposited Nanomaterials for Gas Sensing: Design Strategies, Performance Limits and Machine learning prospects

Abstract

Physical Vapor Deposition (PVD) has been known for producing high-quality thin films for large-area electronics. The application of these films include fabrication of memory devices, solar cells, photodetectors, light-emitting diodes (LEDs), light amplification by stimulated emission of radiation (LASERs), solid-state sensors, etc. A wide range of functional materials, such as pure metals, metal oxides, transition metal dichalcogenides (TMDCs), their alloys, nanocomposites, nanohybrids and heterostructures, can be deposited with precise control over film thickness, composition, and morphology by PVD. This review explores PVD methods for fabricating thin films tailored for gas sensing applications. It highlights how controlled deposition parameters influence sensor performance metrics such as sensitivity, selectivity, response/recovery times, and stability. Various transduction principles, like resistive, capacitive, optical, acoustic, etc., have been covered to explain and highlight the role of quality films produced by PVD techniques for gas sensing. This review provides an overview of the critical role, challenges, and promising future of PVD in depositing innovative gas-sensing materials and tuning their electrical properties for improved sensing behaviour. Special attention is given to future perspectives, including the correlation between PVD fabrication and machine learning for the development of next-generation intelligent sensing platforms.