Enhanced gas sensing capabilities of graphene field-effect transistors for detecting H2S and CO2: a NEGF approach

• GFETs leverage graphene’s conductivity and surface sensitivity for gas detection. • Gas adsorption alters GFET electrical properties, enabling specific gas concentration sensing. • GFET sensitivity to gases varies (3–40%), showing high potential for low concentration detection. • Non-equilibrium Green’s function formalism analyzed time-dependent GFET gas response. • Optimizing GFET performance and selectivity, via functionalization/doping, remains key. This study provides a comprehensive analysis of gas sensors based on graphene field-effect transistors (GFETs) for detecting toxic gases such as hydrogen sulfide (H 2 S) and carbon dioxide (CO 2 ). By utilizing the unique electronic properties of graphene, we explore the interaction between gas molecules and graphene sheets through the non-equilibrium Green’s function (NEGF) formalism. Our findings reveal that the adsorption of H 2 S and CO 2 significantly modifies the electronic properties of graphene, improving its sensitivity and response time. In this work, we demonstrated that the sensitivity for different molecules varies within the range of 3–40, and the charge current changes from the order of magnitude 0.1 to 10. The results suggest that optimized GFET designs can effectively detect low concentrations of harmful gases, making them suitable for environmental monitoring and health safety applications.