Two‐colour THz quantum well photodetectors

Abstract

Two-colour terahertz (THz) quantum-well photodetectors are designed, fabricated, and characterised. To realise two-colour detection, a stacked structure is adopted by sequentially growing two one-colour detectors. It is found that the spectra of the stacked device are in accordance with those of the two individual detectors connected in series. The relatively broad spectral bandwidth may enable its use in a THz spectrometer.