High performance, room temperature, broadband II-VI quantum cascade detector

We report on the experimental demonstration of a room temperature, II-VI, ZnCdSe/ZnCdMgSe, broadband Quantum Cascade detector. The detector consists of 30 periods of 2 interleaved active-absorption regions centered at wavelengths 4.8 μm and 5.8 μm, respectively. A broad and smooth photocurrent spectrum between 3.3 μm and 6 μm spanning a width of 1030 cm–1 measured at 10% above baseline was obtained up to 280 K, corresponding to a ΔE/E of 47%. Calibrated blackbody responsivity measurements show a measured peak responsivity of 40 mA/W at 80 K, corresponding to a detectivity of about 3.1×1010 cmHz/W. Bias dependent photocurrent measurements revealed no significant change in the spectral shape, suggesting an impedance matched structure between the different active regions.