Simulation Based Investigation of Sensing Current with Channel Length and Work Function Variation to Realize Hydrogen Detection

The application of ZnO Thin Film Transistors (TFTs) may create mature and widespread opportunities for feasible and precise detection of gas molecules. As a sustainable and clean energy transporter, hydrogen sensors are expected to perform a demanding role due to its broad flammability range in air in a hydrogen economy. Any leaks in hydrogen energy storage infrastructure, transportation and appliances as well as the entire hydrogen allocation infrastructure must be detected instantly for safety reasons. In this work the focus is on the amalgamation of gas consuming ability of ZnO and current modulating ability of bottom gate top contact TFT (BGTC) for performance analysis using ATLAS module of SILVACO TCAD. The effects of variations of noble metals, channel length, work-function and surface potential on output and transfer characteristics of this structure have been assessed to integrate this investigation in hydrogen sensing environment. The proposed ZnO TFT is built using Schottky source and drain contacts unlike an ohmic contact as in the conventional FET. Contrary to the MESFET this structure preserves the traditional MOS gate stack and utilizes an ohmic gate electrode that lies underneath the source-drain contacts and channel.