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 (∼50 MV/m). The maximum estimated infrared‐to‐THz conversion efficiency is ∼1x10‐5. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)