GaN/AlGaN heterojunction infrared detector responding in 8-14 and 20-70 μm ranges

摘要

A GaN/AIGaN heterojunction interfacial work function internal photoemission infrared detector responding in 8-14 and 20-70 μm ranges has been demonstrated. Free carrier absorption based photoresponse shows a wavelength threshold of 14 μm with a peak responsivity of 0.6 mA/W at 80 K under -0.5 V bias. A sharp peak in the 11-13.6 μm range is observed superimposed on the free carrier response. In addition, the work demonstrates 54 μm (5.5 THz) 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.