Probing of localized terahertz self-mixing in a GaN/AlGaN field-effect transistor

Abstract

<div class="aip-paragraph">In our previous work [Sun <span class="etal">et al.</span>, Appl. Phys. Lett. <strong class="emphbold">100</strong>, 013506 (2012)], we inferred the existence of localized self-mixing in an antenna-coupled field-effect terahertz detector. In this Letter, we report a quasistatic self-mixing model taking into account the localized terahertz fields and its verification by comparing the simulated results with the experimental data in a two-dimensional space of the gate voltage and the drain/source bias. The model well describes the detector characteristics: not only the magnitude, but also the polarity, of the photocurrent can be tuned. The existence of strongly localized self-mixing in such detectors is confirmed.</div