NEGF-Based Analysis of TMDC-Silicon Heterojunction Nanowire Gas Sensors for Oxygen and Hydrogen Detection

Gas sensors play a crucial role in this domain, prompting extensive research efforts. In this study, we analyze a TMDC-Si heterojunction-based gas sensor using the non-equilibrium Green’s function (NEGF) method. The sensor features a cylindrical configuration to minimize area consumption and is evaluated through IDS-VGS characteristics, the density of states at the source and drain electrodes, and transmission probability across the channel. By leveraging the variation in the work function of catalytic metal-based gate electrodes, the proposed sensor demonstrates effective detection of vital gases such as oxygen (O2) and hydrogen (H2). Our findings show that the WS2-Si heterojunction achieves a peak sensitivity of 104 for O2 detection, while MoTe2-Si exhibits superior linearity characteristics for H2 detection despite similar sensitivity across all heterojunctions. These results indicate the potential of the proposed sensor for integration into compact sensing integrated circuits (ICs) in future applications.