High detectivity short-wavelength II-VI quantum cascade detector

Abstract

We report on the experimental demonstration of a ZnCdSe/ZnCdMgSe-based short-wavelength photovoltaic Quantum Cascade Detector (QCD). The QCD operates in two spectral bands centered around 2.6 μm and 3.6 μm. Calibrated blackbody measurements yield a peak responsivity of 0.1 mA/W or 2400 V/W at 80 K, and a corresponding 300 K background radiation limited infrared performance detectivity (BLIP) of ∼2.5 × 1010 cm √Hz/W. Comparison of background illuminated and dark current-voltage measurements demonstrates a BLIP temperature of 200 K. The device differential resistance-area product, decreases from about 106 Ω cm2 at 80 K to about 8000 Ω cm2 at 300 K, indicative of the ultra-low Johnson noise in the detectors.