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Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters
Published on: July 8, 2013
A plasmonic terahertz detector with a monolithic hot electron bolometer.
G C Dyer1, J D Crossno, G R Aizin
1Physics Department, University of California-Santa Barbara, Santa Barbara, CA 93106, USA.
Summary
Researchers developed a novel plasmonic terahertz detector using a grating gated GaAs/AlGaAs high electron mobility transistor. Enhanced responsivity was achieved by introducing a secondary gate, with the hot electron bolometric effect identified as the primary detection mechanism.
Area of Science:
- Terahertz (THz) Optoelectronics
- Semiconductor Device Physics
- Plasmonics
Background:
- High electron mobility transistors (HEMTs) are crucial for high-frequency applications.
- Plasmonic effects in HEMTs offer potential for sensitive THz detection.
- Efficiently controlling and enhancing THz detection mechanisms in HEMTs remains a challenge.
Purpose of the Study:
- To fabricate and characterize a novel plasmonic terahertz detector integrated into a grating gated HEMT.
- To investigate methods for enhancing the responsivity of such THz detectors.
- To determine the dominant physical mechanism responsible for THz detection in the device.
Main Methods:
- Fabrication of a GaAs/AlGaAs HEMT with an integrated voltage-controlled planar barrier and grating gate.
- Experimental characterization of the device's plasmonic response at approximately 405 GHz.
- Bias-dependent measurements of THz responsivity and time constants at 20 K, coupled with DC electrical characterization.
Main Results:
- The fabricated detector exhibited a plasmonic response with a 40 GHz full width at half-maximum at ~405 GHz.
- Introducing an independently biased narrow gate significantly increased the detector's responsivity.
- DC and responsivity measurements at 20 K strongly indicated the hot electron bolometric effect as the main detection mechanism.
Conclusions:
- A novel plasmonic terahertz detector based on a grating gated HEMT with enhanced responsivity has been successfully demonstrated.
- The integration of a voltage-controlled planar barrier and an independently biased gate provides effective control over detector performance.
- The hot electron bolometric effect is confirmed as the dominant mechanism for THz detection in this device configuration at low temperatures.
