Modeling of graphene photodetector based on photogating effect for circuits simulation

Abstract

Abstract Graphene photodetectors based on the photogating effect offer the advantages of high responsivity. However, physical model of these photodetectors which is suitable for circuit design are still missing at present time. This paper aims to develop a physical model of the detector by introducing a ‘virtual back-gate’ method, which translates incident optical power into the Dirac point voltage of the transfer curve. Additionally, a physical model of the detector is established by combining the ‘virtual back-gate’ and ‘photo-gate’. To investigate the relationship between input optical power and photocurrent, a detector PSPICE model is developed using the gate-controlled current sources realized through the ‘virtual back-gate’ and ‘photo-gate’. A capacitive transimpedance amplifier circuit is employed for simulation verification. The research presented in this paper serves as a valuable reference for the circuit design of two-dimensional material photodetectors based on the photogating effect.