InAs/GaAs quantum dots for THz generation

N. S. Daghestani, Maria Ana Cataluna, G. Berry, G. Ross, M. J. Rose

Research output: Contribution to journalArticle

2 Citations (Scopus)

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 (~50 MV/m). The maximum estimated infrared-to-THz conversion efficiency is ~1x10 -5.

Original languageEnglish
Pages (from-to)222-225
Number of pages4
JournalPhysica Status Solidi C - Current Topics in Solid State Physics
Volume9
Issue number2
DOIs
Publication statusPublished - Feb 2012

Keywords

  • Quantum confined materials
  • Terahertz generation
  • Ultrafast processes in semiconductors

ASJC Scopus subject areas

  • Condensed Matter Physics

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