Comparative Study on Readout Circuit for Graphene and Typical Photoconductors Photodetectors

Graphene-based photodetectors have the advantages of good compatibility and wide-band response, and their readout circuits are similar to traditional detectors such as bolometers. However, graphene photodetectors are generally photon types whose responsivity, power consumption, and integration time are significantly different. Here, the readout circuits of pure graphene, graphene-lead sulfide heterostructure, lead sulfide, and typical bolometer combined with the measured device parameters are studied. Simulation results show that because of its high responsivity, when the same output voltage is achieved, the integration time of the graphene-lead sulfide heterostructure detector is the lowest, which is more conducive to high-frame-rate applications. However, compared with the bolometer, the graphene detector has a higher power consumption, and the analysis shows that a reasonable device structure design can effectively reduce the power consumption. This study can provide a reference in the selection of the readout circuit and parameter design of a new type of two-dimensional material photodetector.