Low-bandgap material engineering based TFET device for next-generation biosensor application-A comprehensive review on device structure and sensitivity

The Tunnel Field Effect Transistor (TFET) device has emerged as the potential candidate to replace the Field Effect Transistor (FET)--based biosensor for the label-free detection of biomolecules using the dielectric modulation (DM) technique. The superior subthreshold swing characteristics with the unique band-to-band tunneling (BTBT) of charge carriers, the TFET-based biosensor can accomplish features of Point of Care Testing (PoCT) tools. Researchers proposed various techniques to enhance the performance of TFET-based biosensors in terms of high ON(ION) current sensitivity, which is treated as the performance stumbling block for TFET devices. In this review, a systematic investigation of the low bandgap material engineering technique applied to the TFET-based biosensors is carried out to understand the functionality and work. The heterojunction-based TFET biosensors with SiGe, Ge, and GaAs material are investigated thoroughly. The hetero material-based junction less TFET biosensors are also included in this review to exhibit the advantage of the material engineering approach for JLTFET biosensors. The bandgap engineering technique for the heterojunction TFET biosensor is investigated by considering other performance approaches like structural engineering, Gate work function, and source engineering. The performance of these heterojunction TFET biosensors was studied by taking the parameters like energy bandgap, on current, drain current sensitivity and subthreshold swing of the device. In this work, a detailed roadmap is created to understand how the low bandgap material engineering can be applied to the TFET biosensor to enhance its performance in terms of sensitivity and speed of detection.