Abstract
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
Original language | English |
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Pages (from-to) | 222-225 |
Number of pages | 4 |
Journal | Physica Status Solidi C: Current Topics in Solid State Physics |
Volume | 9 |
Issue number | 2 |
DOIs | |
Publication status | Published - 2012 |
Event | Compound Semiconductor Week 2011: 38th International Symposium on Compound Semiconductors - Berlin, Germany Duration: 22 May 2011 → 26 May 2011 http://conference.vde.com/CSW2011/Pages/Homepage.aspx |