Mechanism and Verification of Photoelectric Regulation Characteristics of Two-Dimensional Photodetectors

Two-dimensional photodetectors have an important property that can improve the optical effect by adjusting the Fermi level, and have outstanding development prospects in the field of visible-infrared photoelectric detection. Here, combined with the surface electronic properties of two-dimensional materials, we analyzed the physical mechanism of the photoelectric effect of a photodetector based on two-dimensional materials. By simulating the light waves of different wavelengths induced on the surface of the photodetector, the changes of its conductivity and absorption rate were analyzed. Since the channel material has an electrically tunable Fermi level, the surface electric field will also be regulated with the Fermi level. Finally, we verified its photoelectric performance by preparing a trilayer graphene device. The results show that the light response of the trilayer graphene photodetector reaches the maximum at 1550 nm, and the surface photoelectric electric field distribution is affected by the Fermi level regulation. Our results show that the performance of graphene photodetectors can be efficiently regulated by Fermi level, which provides theoretical support for the performance improvement and material upgrading of photodetectors in the future.