In this paper, symmetrical design of a double gate dielectric modulated junctionless tunnel field effect transistor (DG-DM-JLTFET) based structure is proposed and investigated and for the first time to inspect label-free recognition of biological molecules like uricase, protein, biotin, aminopropyl- triethoxysilane etc. The point when biological molecules get immobilized in nanocavity area, the variation in the drain current, subthreshold slope, and $I_ON/I_OFF$ ratio has been used as the detecting parameters to recognize the sensitivity of the DG-DM-JLTFET for biomolecule recognition by using tcad simulation. A cavity is designed by etching a layer from the substrate, at the side of the gate electrode A dual metal gate structure is framed by utilizing two unique metal entryway anodes to decrease short channel effects of DG-DM-JLTFET. An examination is exhibited to show the effect of fill-in factor of biological molecules on drain current of DG-DM-JLTFET device. The existence of biological molecules in a small region inside the nanocavity area above the tunneling junction results in variation of the electrical properties of the device. This brings about high sensitivity in terms of drain current, subthreshold slope, and $I_ON/I_OFF$ ratio. The proposed device structure gives perceptible outcomes for both (neutral and charged) types of biological molecules.

Nanoscale devices have great potential for providing a platform for detecting biomolecules. There are a number of difficulties observed during the fabrication process of these devices such as random dopant fluctuation and thermal budget etc. To cut down these problems charge-plasma based concept is introduced. This paper proposes the implementation of charge-plasma based gate underlap dielectric modulated junctionless tunnel field effect transistor (CPB DM-JLTFET) for the label free electrical recognition of biomolecules like cell, enzyme, deoxyribonucleic acid (DNA), protein etc via incorporating the dielectric modulation (DM) technique. A gate underlap region is formed in the device via etching oxide material. Label free detection of biomolecules depends upon the electrical property of biomolecules. The effect of device parameters such as cavity length and cavity thickness on surface potential, subthreshold slope (SS), I ON/I OFF ratio and their sensitivity have been discussed. This paper investigates the performance of CPB DM-JLTFET for biomolecule sensing applications while varying dielectric constant, surface density, cavity length and cavity thickness at different biasing conditions. The device proposed is implemented and simulated by using ATLAS device simulator.