AlGaN/GaN THz resonant plasmonic detectors with symmetric and asymmetric patterns deposited above homogeneous and inhomogeneous 2DEG

Abstract

We investigate plasmonic THz detectors on Al-GaN/GaN hetero-structures for different configurations of the grating (symmetric or asymmetric pattern) and spatial modulation of the electron sheet density. The absorption spectra have been calculated for the different configurations and a few detectors have freshly been fabricated and the transmission and reflection spectra have been measured for one of them. It appears that these detectors could be the ideal candidate for an on-chip, electrically tunable, room-temperature operating and cheap THz detector.

Terahertz magnetoplasmon-polaritons with nonlocal corrections for lossy two dimensional electron gas in GaN-based heterostructures

“…Terahertz (THz) plasmon-polaritons refer to the coupling modes between photons (THz radiation) and plasmons (collective excitations of two dimensional electron gas (2DEG)). Properties of 2D plasmons in III-V [1][2][3][4][5], IV-IV [6][7][8] and II-VI [9,10] semiconductor heterostructures and in new materials, like graphene [11], have been studied theoretically and experimentally in the application areas of THz emitters and detectors. The coupling mechanism between THz radiation and 2D plasmons is realized conveniently by metallic gratings on top of the semiconductor barrier layer.…”

“…Section 2 derives the general formula for the calculation of MPP complex frequencies and absorptions according to the structural and physical parameters in the heterostructure with grating couplers. Taking the AlGaN/GaN structure as a case study, we compute the real and imaginary parts of the MPP frequencies and the absorption spectrum at different wavevectors and magnetic field taking advantage of the slightly modified homemade program based on coupled wave method (CWM) [5,8,15] in section 3. Influences of nonlocal correction terms in the magnetoconductivity and contributions of phonons in polar semiconductors, polarization of the incident THz field and retardation effects are also discussed.…”