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Author Kim, S. ♦ Wolters, R. H. ♦ Heath, J. R.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword PHYSICS ♦ INDIUM PHOSPHIDES ♦ PHOTOLUMINESCENCE ♦ FREQUENCY DEPENDENCE ♦ TEMPERATURE DEPENDENCE ♦ EXCITONS ♦ EXCITED STATES ♦ PARTICLE SIZE ♦ QUANTUM DOTS
Abstract We report here on the size-dependent kinetics of exciton recombination in a III{endash}V quantum dot system, InP. The measurements reported include various frequency dependent quantum yields as a function of temperature, frequency dependent luminescence decay curves, and time-gated emission spectra. This data is fit to a three-state quantum model which has been previously utilized to explain photophysical phenomena in II{endash}VI quantum dots. The initial photoexcitation is assumed to place an electron in a (delocalized) bulk conduction band state. Activation barriers for trapping and detrapping of the electron to surface states, as well as activation barriers for surface-state radiationless relaxation processes are measured as a function of particle size. The energy barrier to detrapping is found to be the major factor limiting room temperature band-edge luminescence. This barrier increases with decreasing particle size. For 30 A particles, this barrier is found to be greater than 6 kJ/mol{emdash}a barrier which is more than an order of magnitude larger than that previously found for 32 A CdS nanocrystals. {copyright} {ital 1996 American Institute of Physics.}
ISSN 00219606
Educational Use Research
Learning Resource Type Article
Publisher Date 1996-11-01
Publisher Department Lawrence Berkeley National Laboratory
Publisher Place United States
Journal Journal of Chemical Physics
Volume Number 105
Issue Number 18
Organization Lawrence Berkeley National Laboratory


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