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

Journal Article · Mon Jul 28 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4891223· OSTI ID:22308552

Wagener, M. C.; Botha, J. R. ^[1]; Carrington, P. J. ^[2]; Krier, A. ^[3]

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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)

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.

• OSTI ID: 22308552
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

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