Ga N ∕ Al Ga N heterojunction infrared detector responding in 8–14 and 20–70μm ranges

Abstract

A GaN∕AlGaN heterojunction interfacial work function internal photoemission infrared detector responding in 8–14 and 20–70μm ranges has been demonstrated. Free carrier absorption based photoresponse shows a wavelength threshold of 14μm with a peak responsivity of 0.6mA∕W at 80K under −0.5V bias. A sharp peak in the 11–13.6μm range is observed superimposed on the free carrier response. In addition, the work demonstrates 54μm (5.5THz) operation of the detector based on 1s–2p± transition of Si donors in GaN. Possible approaches on improving the performance of the detector are also addressed.