Hot-carrier cooling in GaAs: Quantum wells versus bulk

Journal Article · Mon Nov 15 00:00:00 EST 1993 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.48.14675· OSTI ID:5653197

Rosenwaks, Y; Hanna, M C; Levi, D H; Szmyd, D M; Ahrenkiel, R K; Nozik, A J ^[1]

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1. National Renewable Energy Laboratory, Golden, Colorado 80401 (United States)

Hot-electron cooling dynamics in photoexcited bulk and quantum-well GaAs structures were determined using time-correlated single-photon counting of photoluminescence (PL) decay. Hot-electron cooling curves were generated from analyses of the time-resolved PL spectra. The time constant characterizing the hot-electron energy-loss rate, [tau][sub avg], was then determined, taking into account electron degeneracy and the time dependence of the quasi-Fermi-level. This analysis was also applied to earlier data obtained by Pelouch [ital et] [ital al]. with the same samples, but based on PL up-conversion experiments with [lt]80 fs temporal resolution. Both sets of experiments and analyses show that the hot-electron cooling rate can be much slower in GaAs quantum wells compared (at the same photogenerated carrier density) to bulk GaAs when this density is above a critical value. This critical density was found to range from high 10[sup 17] to low 10[sup 18] cm[sup [minus]3], depending upon the experimental technique; at the highest carrier densities, values of [tau][sub avg] for quantum wells were found to be many hundreds of ps.

• OSTI ID: 5653197
• Journal Information: Physical Review, B: Condensed Matter; (United States), Vol. 48:19; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
GALLIUM ARSENIDES
CHARGED-PARTICLE TRANSPORT
PHOTOLUMINESCENCE
ENERGY LOSSES
FERMI LEVEL
SOLID-STATE PLASMA
ARSENIC COMPOUNDS
ARSENIDES
ENERGY LEVELS
GALLIUM COMPOUNDS
LOSSES
LUMINESCENCE
PLASMA
PNICTIDES
RADIATION TRANSPORT
360606* - Other Materials- Physical Properties- (1992-)