Highly efficient and electrically robust carbon irradiated semi-insulating GaAs based photoconductive terahertz emitters
- Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India)
We demonstrate here an efficient photoconductive THz source with low electrical power consumption. We have increased the maximum THz radiation power emitted from SI-GaAs based photoconductive emitters (PCEs) by two orders of magnitude. By irradiating the SI-GaAs substrate with Carbon-ions up to 2 μm deep, we have created lot of defects and decreased the lifetime of photo-excited carriers inside the substrate. Depending on the irradiation dose, we find 1 to 2 orders of magnitude decrease in total current flowing in the substrate, resulting in subsequent decrease of heat dissipation in the device. This has resulted in increasing maximum cut-off of the applied voltage across PCE electrodes to operate the device without thermal breakdown from ∼35 V to >150 V for the 25 μm electrode gaps. At optimum operating conditions, carbon irradiated (10{sup 14} ions/cm{sup 2}) PCEs give THz pulses with power about 100 times higher in comparison to the usual PCEs on SI-GaAs and electrical to THz power conversion efficiency has improved by a factor of ∼800.
- OSTI ID:
- 22283195
- Journal Information:
- Applied Physics Letters, Vol. 104, Issue 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARBON
CARBON IONS
CHARGE CARRIERS
COMPARATIVE EVALUATIONS
ENERGY LOSSES
GALLIUM ARSENIDES
HEAT TRANSFER
ION BEAMS
IRRADIATION
LIFETIME
PHOTOCONDUCTIVITY
RADIATION DOSES
RADIATION EFFECTS
SILICON
SUBSTRATES
THERMAL DIFFUSIVITY
THZ RANGE