GaAs/AlGaAs quantum well infrared photodetector with low noise

A novel kind of multi-quantum well infrared photodetector (QWIP) is presented. In the new structure device, a p-type contact layer has been grown on the top of the conventional structure of QWIP, then a small tunneling current is instead of the large compensatory current, which made the device low dark current and low noise characteristics. The measured result of dark current is consistent with the calculated result, and the noise of the new structure QWIP is decreased to one third of the conventional QWIP.