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Title: Direct detector for terahertz radiation

Abstract

A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.

Inventors:
 [1];  [1];  [1];  [2]
  1. Albuquerque, NM
  2. Santa Barbara, CA
Issue Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
943498
Patent Number(s):
7420225
Application Number:
11/290,090
Assignee:
Sandia Corporation (Albuquerque, NM)
Patent Classifications (CPCs):
B - PERFORMING OPERATIONS B82 - NANOTECHNOLOGY B82Y - SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES
H - ELECTRICITY H01 - BASIC ELECTRIC ELEMENTS H01L - SEMICONDUCTOR DEVICES
DOE Contract Number:  
AC04-94AL85000
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION

Citation Formats

Wanke, Michael C, Lee, Mark, Shaner, Eric A, and Allen, S James. Direct detector for terahertz radiation. United States: N. p., 2008. Web.
Wanke, Michael C, Lee, Mark, Shaner, Eric A, & Allen, S James. Direct detector for terahertz radiation. United States.
Wanke, Michael C, Lee, Mark, Shaner, Eric A, and Allen, S James. Tue . "Direct detector for terahertz radiation". United States. https://www.osti.gov/servlets/purl/943498.
@article{osti_943498,
title = {Direct detector for terahertz radiation},
author = {Wanke, Michael C and Lee, Mark and Shaner, Eric A and Allen, S James},
abstractNote = {A direct detector for terahertz radiation comprises a grating-gated field-effect transistor with one or more quantum wells that provide a two-dimensional electron gas in the channel region. The grating gate can be a split-grating gate having at least one finger that can be individually biased. Biasing an individual finger of the split-grating gate to near pinch-off greatly increases the detector's resonant response magnitude over prior QW FET detectors while maintaining frequency selectivity. The split-grating-gated QW FET shows a tunable resonant plasmon response to FIR radiation that makes possible an electrically sweepable spectrometer-on-a-chip with no moving mechanical optical parts. Further, the narrow spectral response and signal-to-noise are adequate for use of the split-grating-gated QW FET in a passive, multispectral terahertz imaging system. The detector can be operated in a photoconductive or a photovoltaic mode. Other embodiments include uniform front and back gates to independently vary the carrier densities in the channel region, a thinned substrate to increase bolometric responsivity, and a resistive shunt to connect the fingers of the grating gate in parallel and provide a uniform gate-channel voltage along the length of the channel to increase the responsivity and improve the spectral resolution.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2008},
month = {9}
}

Works referenced in this record:

Terahertz plasma wave resonance of two-dimensional electrons in InGaP∕InGaAs∕GaAs high-electron-mobility transistors
journal, September 2004


Resonant detection of subterahertz and terahertz radiation by plasma waves in submicron field-effect transistors
journal, December 2002


Terahertz photoconductivity and plasmon modes in double-quantum-well field-effect transistors
journal, August 2002


Single-quantum-well grating-gated terahertz plasmon detectors
journal, November 2005


Millimeter wave mixing using plasmon and bolometric response in a double-quantum-well field-effect transistor
journal, January 2005


High sensitivity Si-based backward diodes for zero-biased square-law detection and the effect of post-growth annealing on performance
journal, July 2005