Title

Inp- And Graphene-Based Grating-Gated Transistors For Tunable Thz And Mm-Wave Detection

Keywords

2DEG; HEMT; Plasmon; Terahertz

Abstract

Plasmon excitation in the two dimensional electron gas (2DEG) of grating-gated high electron mobility transistors (HEMTs) gives rise to terahertz absorption lines, which may be observed via transmission spectroscopy. Such absorption resonances may alter the channel conductance, giving a means for tunable terahertz detection. The transmission spectrum may be calculated analytically by making simplifying assumptions regarding the electron distribution. Such assumptions can limit the usefulness of such analytical theories for device optimization. Indeed, significant differences between experimentally observed resonances and theory have been noted and explained qualitatively as due to additional, unanticipated, sheets of charge in the device. Here, we explore finite element method (FEM) simulations, used to obtain realistic carrier profiles. Simulated plasmon spectra do not support previous explanations of red-shifting due to interactions with additional neighboring charge distributions. Simulations do show unexpected plasmon resonances associated with the unanticipated sheet charge, named virtual-gate, as well as the expected resonances associated with the 2DEG. Plasmonic modes determined from these investigations are able to account for the measured absorption lines which were previously thought to be red-shifted 2DEG plasmons. Additionally, the same simulation approach was applied to proposed graphene-based devices to investigate their plasmon resonance spectra. © 2012 SPIE.

Publication Date

7-23-2012

Publication Title

Proceedings of SPIE - The International Society for Optical Engineering

Volume

8373

Number of Pages

-

Document Type

Article; Proceedings Paper

Personal Identifier

scopus

DOI Link

https://doi.org/10.1117/12.918660

Socpus ID

84863953193 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/84863953193

This document is currently not available here.

Share

COinS