Physics and optoelectronic simulation of photodetectors based on 2D materials

2D-material-based photodetectors (2DMPDs) have attracted broad interest due to their many unique benefits (e.g., their giant photoresponsivity). However, a thorough device-level simulation, which takes into account optical absorption, electrical transportation, and semiconductor material properties, is still challenging. This study reports the realization of a comprehensive optoelectronic simulation of 2DMPDs in multidimensional and multiphysics domains. This work begins with a simulation of conventional monolayer photoresistor detectors by introducing basic theories and simulation technologies. In particular, the trap effect, which is highly important for regulating the photoresponse of 2D devices, is successfully introduced into the simulation so that very good agreement between the simulation and an experiment is realized. The simulation is extended to popular monolayer phototransistors so that precise quantitative evaluations of the optoelectronic device performance, such as the output characteristics, transfer properties, responsivity, response time, and detectivity, become very convenient. Furthermore, a time-domain device simulation is implemented, which allows to study the modulation characteristics of 2DMPDs. The device-level simulation provides a useful platform for studying and optimally designing advanced 2DMPDs. For example, this simulation is convenient for studying the balance between photoresponsivity and response time in 2DMPDs.