Asymmetric Dual-Gate Junctionless GNR Tunnel FET as a High-Performance Photosensor With an Electrostatically Improved Photosensitivity: A Quantum Simulation Study

In this article, a new asymmetric dual-gate junctionless graphene nanoribbon tunneling field-effect phototransistor (DG JL-GNRTFEP) has been proposed using a quantum simulation approach. The developed computational approach is based on solving the nonequilibrium Green’s function formalism self-consistently coupled with Poisson’s equation including the light-induced electrostatic potential modulation. The photosensing principle of the ballistic nanophototransistor is normally based on light-induced gate photovoltage. The main aim of the proposed design is to improve the photosensitivity electrostatically using an asymmetry in terms of coupling capacitances. The computational study has included light-induced modulation in threshold voltage, drain current, electrostatic potential, and current spectrum. In addition, a parametric investigation has been conducted considering different top-to-back capacitance ratios, revealing that the effect of the light-induced gate photovoltage on the drain current can be significantly amplified while decreasing the aforementioned coupling capacitance ratio. The proposed improvement strategy, which is based on asymmetric coupling capacitances, remains valid even using other photosensitive gates able to induce photovoltage.