A novel TFET based nanogap high-sensitive biosensor by boosted reliability- new metric for sensitivity definition

This is a detailed report about the proposal of an efficient nanogap dielectrically modulated tunnel field-effect transistor (TFET) biodevice granting a high sensitivity in the detection of the targeted biomolecules while keeping high performance in the realistic situations with boosting the reliability. Two attractive approaches in the cases of the bandgap engineering and charge plasma concept have been suggested for the band energy correction increasing the sensing current and the sensitivity without occurrence possibility of fabrication process related issues as compared to common TFET and PNPN TFET biosensors. The streptavidin, biotin and APTES samples have been selected as typical biomolecules for the sensing performance comparison of the biosensors under the study. Also, the proposed biosensor showed performance superiority for other biomolecules. For the first time, a new metric for measuring sensitivity is proposed to combine both maximum current sensitivity and well-defined average sensitivity in a unique relation named effective sensitivity. This prevents the possible noise impact on the sensitivity of the biosensors since the TFET based biosensors suffer from the low detection current. Defining the effective sensitivity, the proposed biosensor has been evaluated in more realistic conditions including partial hybridization of biomolecules inside the nanogap, trap-assisted-tunneling (TAT) component, neutral/charged biomolecules and biomolecules accumulation in different orientations showing the performance superiority of the proposed biosensor.