Performance of high-sensitivity quantum Hall far infrared photodetectors

We have characterized the performance of a newly developed far-infrared photodetector which utilizes the cyclotron resonance of two-dimensional electrons in modulation-doped Al0.3Ga0.7As/GaAs heterojunctions in the integer quantum Hall regime. It is found that the responsivity and the detectivity of the present device reach as high as 1.1×107 V/W and 4.0×1013 cm Hz1/2/W, respectively, at 4.2 K. The quantum Hall photodetector is very promising as a high-sensitivity, narrowband tunable photodetector in the far infrared range.