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

TL;DR

This paper presents a GaN/AlGaN quantum cascade detector operating at 5.7 THz, demonstrating high-quality material growth, specific spectral response, and temperature-dependent photocurrent performance.

Contribution

It introduces a novel GaN/AlGaN quantum cascade detector based on polar step quantum wells with high structural quality and terahertz detection capabilities.

Findings

Peak photocurrent at 5.7 THz with 0.1 mA/W responsivity at 10 K

Device maintains photocurrent up to 20 K

High structural quality of grown nitride material

Abstract

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 um period grating. The photocurrent persists up to 20 K.