Gas Sensing with Two-Dimensional Materials Beyond Graphene

The semiconductor industry is intensely working towards the functional integration of devices beyond digital logic, such as sensors and RF circuits, on the same chip. For gas sensors, this requires that future devices can be fabricated with the same technologies as future digital logic transistors, likely using mature complementary metal oxide semiconductor (CMOS) fabrication techniques, due to the inherent low costs and scalability they offer. While chemoresistive semiconductor metal oxide (SMO) sensors have garnered significant attention in the last decades, resulting in their commercialization, they require high temperatures to initiate the surface chemical reactions for sensing, meaning that a complex integration of a microheater on a MEMS structure is required. This is not ideal and room temperature solutions are readily sought after. Two-dimensional (2D) materials appear to offer precisely that: Potential for integration with CMOS technology, while also being highly sensitive to many relevant gases at room temperature. This manuscript explores several types of 2D materials which have the potential to be used as channel materials in digital logic transistors and sensing films, due to the presence of a relatively wide band gap. Therefore, this excludes graphene from our discussion and we look into recent gas sensing trends with reduced graphene oxide, transition metal dichalcogenides (TMDs), and phospho-rene and arsenene.