Design and Performance Analysis of Polarity Control Junctionless TFET (PC-JL-TFET)-Based Biosensor

Abstract

This paper proposes a novel polarity-control junctionless tunnel field-effect transistor (PC-JL-TFET)-based biosensor for the label-free detection of biomolecule species in efficient ways. Unlike conventional designs, the polarity-control concept induces the generation of drain (n[Formula: see text]) and source (p[Formula: see text]) regions inside the proposed structure when a bias of [Formula: see text] is applied at the polarity gates-1/2 (PG-1/2), to form a conventional TFET. To capture the biomolecules, a nano-cavity is created within the source region’s dielectric oxide toward the tunneling interface. The presence of biomolecules is electronically detected based on either solely the dielectric constant (neutral biomolecules) or the combination of charge density and dielectric constant (charged biomolecules). The proposed device can perform label-free recognition of biomolecules such as Uricase, Keratin, Biotin, Streptavidin and so on. To investigate the sensing performance of the proposed biosensor, significant biosensing metrics such as the electric field, energy band diagram, tunneling current, subthreshold slope, [Formula: see text] ratio and threshold voltage have been studied. The proposed PC-JL-TFET biosensor achieves a maximum sensitivity of [Formula: see text] for neutral biomolecules with a dielectric constant of 12 and [Formula: see text] for negatively charged biomolecules [Formula: see text] with a dielectric constant of 8. The proposed biosensor’s selectivity, linearity and temperature-based analysis have also been evaluated for different biomolecules. Additionally, real-time practical scenarios, such as partially filled nano-cavities and the random position of biomolecules in the nano-cavity-based analysis, have also been incorporated.