Figure 4.

Architecture and schematic diagram of 2D nanomaterials-based micro spectrometers. (a) Schematic diagram of the graphene-based Fabry–Pérot spectrometer. Surface plasmon polaritons (SPPs) in graphene propagate across two Bragg reflectors and a bridge between them that are modulated by different voltages. The arrow at the top of the graphene layer indicates the direction of SPPs propagation [78]. Copyright 2016, Scientific Reports. (b) Schematic of the graphene ribbons and MoS₂ vertical heterostructure photodetector [79]. Copyright 2018, Nanoscale. (c) Schematic of the BP spectrometer. Gr, graphene [80]. Copyright 2021, Nature Photonics. (d) Schematic diagram of a typical dual-gate BP transistor. The applied top and bottom gate voltages (V_TG and V_BG, respectively) can control the carrier density and the electric displacement field in the sample [81]. Copyright 2022, Applied Physics Letters. (e) Schematic view of the 2D-vdWH spectrometer. V_ds and V_bg are bias voltage and back gate voltage, respectively. ‘hv’ and the red arrow indicate the incident light [82]. Copyright 2022, Nature communications. (f) Schematic of the MoS₂/WSe₂ heterojunction spectrometer [83]. Copyright 2022, Science.