skip to main content

Title: Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings

The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudo-monochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo- and thermal-emission characteristics of the quantum rings.
Authors:
;  [1] ;  [2] ;  [3]
  1. Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth 6031 (South Africa)
  2. Department of Electronic and Electrical Engineering, University College London, London (United Kingdom)
  3. Department of Physics, Lancaster University, Lancaster LA1 4YB (United Kingdom)
Publication Date:
OSTI Identifier:
22308552
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION; CHARGE STATES; CROSS SECTIONS; GALLIUM ANTIMONIDES; GALLIUM ARSENIDES; LIGHT SOURCES; MONOCHROMATIC RADIATION; PHOTOEMISSION; PHOTONS; SOLAR CELLS; TEMPERATURE DEPENDENCE