Two-band ZnCdSe/ZnCdMgSe quantum well infrared photodetector

Abstract

An independently controllable, two-band quantum well infrared photo-detector (QWIP) based on the ZnCdSe/ZnCdMgSe material system is characterized. The two-band detector consists of two stacks of quantum wells absorbing in the mid- and long-wavelength infrared regime. Photocurrent and responsivity measurements resulted in 11 mA/W and 7 mA/W peak responsivities at 80 K with corresponding detectivities of 2 × 108 cm√Hz/W and 2 × 107 cm√Hz/W centered at 4.8 μm (258 meV) and 7.6 μm (163 meV). The two-band device can also perform as a broadband detector covering wavelengths from 4.4 μm (281 meV) to 8.2 μm (151 meV) at 80 K with a full width at half maximum of 130 meV. Two-band QWIP is tested for an absolute temperature detection application and good agreement is observed between theoretical calculation and experimental results.