Performance analysis of broadband Mid-IR graphene-phototransistor using strained black phosphorus sensing gate: DFT-NEGF investigation

In this work, a new high-performance broadband Infrared Optically Controlled Graphene FieldEffect Transistor (IR-OC-GFET) using strained black phosphorus sensing gate is proposed and investigated. The impact of the hydrostatic pressure on the optoelectronic properties of bulk Black Phosphorus (BP) is studied using density functional theory (DFT) calculations, including Perdew-Burke-Ernzerhof Generalized Gradient Approximation (PBE-GGA) and the screened hybrid (YS-PBE0) function with van der Waals correction. It is revealed that the electronic and the optical properties of BP were substantially affected by the pressure effects, where the band gap energy decreases with increasing the hydrostatic pressure. The phototransistor drain current is calculated by self-consistently solving the Schrodinger/Poisson equations based on Non-Equilibrium Green's function (NEGF) approach. The impact of strained BP sensing gate material on the device sensing properties is investigated. It is found that the proposed device with strained sensing gate provides enhanced optical performances over the middle infrared (Mid-IR) spectral band, making it a new potential alternative photoreceiver for chip-level optical communications.

Automated summary

In this study, a new high-performance broadband infrared optically controlled graphene field-effect transistor with a strained black phosphorus sensing gate is proposed and investigated. The effect of hydrostatic pressure on the optoelectronic properties of black phosphorus is studied, revealing a decrease in band gap energy with increasing pressure. The impact of strained black phosphorus sensing gate on device sensing properties is also investigated, showing enhanced optical performances.