A 5.7-THz GaN/AlGaN quantum cascade detector based on polar step quantum wells

We report on a GaN/AlGaN quantum cascade detector operating in the terahertz spectral range. The device was grown by metal organic chemical vapor deposition on a c-sapphire substrate and relies on polar GaN/AlGaN step quantum wells. The active region thickness is in micrometer range. The structural, electrical, and optical investigations attest of high structural quality of the synthetized nitride material. The detector exhibits a peak photocurrent at 5.7 THz (23.6 meV) with a responsivity of 0.1 mA/W at 10 K under surface normal irradiation through a 10 mu m period grating. The photocurrent persists up to 20 K. Published under an exclusive license by AIP Publishing.

Automated summary

We report on a GaN/AlGaN quantum cascade detector operating in the terahertz spectral range. The detector exhibited a peak photocurrent at 5.7 THz with a responsivity of 0.1 mA/W at 10 K. The device was grown by metal organic chemical vapor deposition on a c-sapphire substrate and relied on polar GaN/AlGaN step quantum wells.