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A Photonic System for Generating Unconditional Polarization-Entangled Photons Based on Multiple Quantum Interference
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A multimode photodetector with polarization-dependent near-infrared responsivity using the tunable split-dual gates
Zhou Zhang1,2, Junxin Chen1,2, Hao Jia3
1School of Electronics and Information Technology, Sun Yat-sen University, Guangzhou 510006, China.
Iscience
|October 7, 2022
Summary
Researchers developed a near-infrared photodetector using twisted bilayer graphene. This device, controlled by coplanar split-gates, demonstrates tunable responsivity linked to polarization and cavity modes, governed by the photothermoelectric effect.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Optoelectronics
Background:
- Two-dimensional (2D) materials enable electrostatic control of carrier densities for p-n junctions.
- Coplanar split-gate configurations in 2D materials are suitable for photodetectors and light-emitting diodes.
- The polarization-dependent responsivity in the near-infrared band remains underexplored.
Purpose of the Study:
- To fabricate and investigate a near-infrared tunable photodetector using twisted bilayer graphene.
- To understand the photovoltage mechanism and polarization dependence in a coplanar split-gate configuration.
- To elucidate the role of cavity modes in device responsivity.
Main Methods:
- Fabrication of a near-infrared tunable multiple modes twisted bilayer graphene photodetector.
- Utilizing coplanar split-gate control for device tuning.
- Experimental analysis of polarization-dependent responsivity and photovoltage mechanisms.
Main Results:
- The photothermoelectric effect was confirmed as the governing mechanism for the photovoltage in the p-n junction mode.
- Tunable multiple modes and polarization-dependent responsivity were observed.
- Discrepancies in responsivity under different linear polarizations were attributed to distinct cavity modes.
Conclusions:
- The photothermoelectric effect is key to the photovoltage mechanism in these 2D material photodetectors.
- Cavity modes significantly influence the polarization-dependent responsivity of the device.
- This work offers insights for designing integrated optoelectronic devices with tunable polarization responses.
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