Investigation of charge plasma-enhanced tunnel field-effect transistor for hydrogen gas sensing application

In this letter, a transducer sensor is introduced that is based on the principle of charge plasma-enhanced tunnel field-effect transistor (CPE-TFET) structure for catalytic metal gate based electrochemical hydrogen (H₂) gas detection using numerical device simulation. In the proposed sensor, the induced charge plasma at the source region is exploited for realizing a superior gate control over tunneling junction electrostatics that leads to a drain current sensitivity improvement near an order of magnitude over the conventional (Conv) TFET. The underlying physics of the proposed sensor is explored from a detailed electrostatic analysis of the tunneling junction in the context of gas molecule adsorption. In this effect, the sensitivity is estimated for the different gate and drain biases, and the suitable biasing range of operation is indicated. Furthermore, extensive structural optimization is performed to achieve a design-level understanding of CPE-TFET. Finally, the comparative performance analysis with Conv-TFET and mosfet establishes the inherent superiority of CPE-TFET for H₂ gas sensing at different partial gas pressures and temperatures.