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Title: The impact of quantum dot filling on dual-band optical transitions via intermediate quantum states

InAs/GaAs quantum dot infrared photodetectors with different doping levels were investigated to understand the effect of quantum dot filling on both intraband and interband optical transitions. The electron filling of self-assembled InAs quantum dots was varied by direct doping of quantum dots with different concentrations. Photoresponse in the near infrared and middle wavelength infrared spectral region was observed from samples with low quantum dot filling. Although undoped quantum dots were favored for interband transitions with the absence of a second optical excitation in the near infrared region, doped quantum dots were preferred to improve intraband transitions in the middle wavelength infrared region. As a result, partial filling of quantum dot was required, to the extent of maintaining a low dark current, to enhance the dual-band photoresponse through the confined electron states.
Authors:
 [1] ; ;  [2]
  1. Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)
  2. Department of Electrical Engineering, 3217 Bell Engineering Center, University of Arkansas, Fayetteville, Arkansas 72701 (United States)
Publication Date:
OSTI Identifier:
22494797
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 118; Journal Issue: 8; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CONCENTRATION RATIO; CRYSTAL DOPING; CURRENTS; DOPED MATERIALS; ELECTRONS; EXCITATION; GALLIUM ARSENIDES; INDIUM ARSENIDES; PHOTODETECTORS; QUANTUM DOTS; QUANTUM STATES; WAVELENGTHS