Dielectric modulated overlapping gate-on-drain tunnel-FET as a label-free biosensor

In this paper, based on the concept of dielectric-modulation, we have proposed a tunnel field effect transistor (TFET) biosensor with a nanogap created by overlapping the gate on the drain side. Sensing in the proposed device is due to a change in the ambipolar current of the transistor when biomolecules with different dielectric constant are immobilized in the nanogap. The maximum ratio of the drain current with absence and presence of biomolecules, which indicates the sensitivity, is as high as 1010. In comparison to other field effect transistor (FET) based biosensors, using TFET as a biosensor not only gives higher sensitivity but also the advantage of low leakage.