InAs/GaAs quantum dots for THz generation. / Daghestani, N. S.; Cataluna, M. A.; Berry, G.; Ross, G.; Rose, M. J.
In: Physica Status Solidi C: Current Topics in Solid State Physics, Vol. 9, No. 2, 2012, p. 222-225.Research output: Contribution to journal › Article
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TY - JOUR
T1 - InAs/GaAs quantum dots for THz generation
A1 - Daghestani,N. S.
A1 - Cataluna,M. A.
A1 - Berry,G.
A1 - Ross,G.
A1 - Rose,M. J.
AU - Daghestani,N. S.
AU - Cataluna,M. A.
AU - Berry,G.
AU - Ross,G.
AU - Rose,M. J.
PY - 2012
Y1 - 2012
N2 - <p>We report pulsed terahertz generation from InAs/GaAs quantum-dot based photoconductive devices. For 800 nm optical excitation, the dots act as recombination centres for carriers generated in the GaAs layers. Using photoreflective pump-probe measurements we demonstrate that the photogenerated carrier lifetime decreases when a lateral bias is applied. This can be attributed to an increase in the capture area of the dots when under bias. Two types of antenna metallization were investigated; non-Ohmic, and quasi-Ohmic contacts. Non-Ohmic antennae displayed resilience to Joule heating when operated at a field strength of 46 MV/m. The breakdown field of the devices was 48 MV/m, which is comparable to the breakdown field of bulk GaAs (similar to 50 MV/m). The maximum estimated infrared-to-THz conversion efficiency is similar to 1x10(-5). (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim</p>
AB - <p>We report pulsed terahertz generation from InAs/GaAs quantum-dot based photoconductive devices. For 800 nm optical excitation, the dots act as recombination centres for carriers generated in the GaAs layers. Using photoreflective pump-probe measurements we demonstrate that the photogenerated carrier lifetime decreases when a lateral bias is applied. This can be attributed to an increase in the capture area of the dots when under bias. Two types of antenna metallization were investigated; non-Ohmic, and quasi-Ohmic contacts. Non-Ohmic antennae displayed resilience to Joule heating when operated at a field strength of 46 MV/m. The breakdown field of the devices was 48 MV/m, which is comparable to the breakdown field of bulk GaAs (similar to 50 MV/m). The maximum estimated infrared-to-THz conversion efficiency is similar to 1x10(-5). (C) 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim</p>
U2 - 10.1002/pssc.201100253
DO - 10.1002/pssc.201100253
M1 - Article
JO - Physica Status Solidi C: Current Topics in Solid State Physics
JF - Physica Status Solidi C: Current Topics in Solid State Physics
SN - 1862-6351
IS - 2
VL - 9
SP - 222
EP - 225
ER -