Modeling of an electrically tunable quantum dot photodetector for terahertz detection

Wei Wu*, Dibyendu Dey, Omer G. Memis, Hooman Mohseni

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations


The terahertz region (1-10 THz) has potential applications in many areas, such as chemical sensing, medical imaging and free-space optical communications. With the demonstration of terahertz sources, it is quite necessary to develop the detection technology in terahertz. Here we propose an electrically tunable quantum dot infrared photodetector to detect the terahertz region. The proposed detector applies a lateral electrical confinement on the quantum wells and forms a quantum disk in the quantum well area. The two-dimensional quantum confinement of quantum disk combining the vertical confinement from the quantum barrier forms a quantum dot structure. Using the energy states and intersublevel energy spacing in the quantum dot, the detector can be used to detect the terahertz region. Changing the lateral electrical confinement, the intersublevel energy spacing can also be tuned and in hence different wavelengths can be detected. Our modeling and simulation results show the tunability of peak detection wavelength of the photodetector from ∼3.3 to ∼6.0 THz with a gate voltage applied on the detector from -2 to -5 V. The peak absorption coefficients of the detection are shown in the range of 103 cm -1. Compared with current quantum dot photodetectors produced by self-assembled growth method the detector proposed here is easier to be tuned and the effective sizes have a much higher uniformity, because of using electrical confinement.

Original languageEnglish (US)
Title of host publicationTerahertz Technology and Applications III
StatePublished - May 3 2010
EventTerahertz Technology and Applications III - San Francisco, CA, United States
Duration: Jan 27 2010Jan 28 2010

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
ISSN (Print)0277-786X


OtherTerahertz Technology and Applications III
Country/TerritoryUnited States
CitySan Francisco, CA


  • Electrical confinement
  • Photodetector
  • Quantum dots
  • Terahertz
  • Tunability

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering


Dive into the research topics of 'Modeling of an electrically tunable quantum dot photodetector for terahertz detection'. Together they form a unique fingerprint.

Cite this