Quantum Hall Dual-Band Infrared Photodetector

Abstract

We have developed a hybrid quantum Hall midinfrared (QHMIR)-quantum Hall far-infrared (QHFIR) photodetector by the use of graphene-GaAs/(Al,Ga)As-layered composite material. Both MIR and FIR photoresistance are observed in a single chip by utilizing cyclotron resonance in the quantum Hall regimes of graphene and two-dimensional electron gas (2DEG) in GaAs/(Al,Ga)As heterostructure, respectively. By cooperatively operating 2DEG as a back-gate electrode to change the carrier density of graphene or graphene as a top-gate electrode to modulate the carrier density of 2DEG with an applied gate voltage less than 1 V and applying the magnetic field to tune cyclotron resonance, we achieve a wide frequency selectivity, covering 640-790 cm-1 for the graphene-QHMIR detector and 24-89 cm-1 for the 2DEG-QHFIR detector. Moreover, our design integrates a log-periodic antenna with the detector to minimize the device size, while preserving high sensitivity. Our results pave the way for implementing a highly tunable MIR-to-FIR photodetector and a dual-band (MIR-FIR) imaging array.