High performance very long wave infrared quantum cascade detector

In this letter, we introduce a very long wave infrared Quantum Cascade Detector (QCD) with a peak response wavelength of 14.5 μm based on a twin-well coupled absorption region design. Different to standard, single transition well QCDs, the twin-well design effectively enhances the absorption strength of the device and broadens the response spectrum to a certain extent. At 77 K, we observed a responsivity of 3.51 mA / W and a Johnson noise limited detectivity of 1×108 Jones. Altogether, this design resulted in detection at temperatures of up to 140 K with a calibrated black-body source by light coupling using a 45° wedge. These high performance very long wave QCDs are expected to provide pollution monitoring, deep space exploration and other applications.