Thermodynamics of biexcitons in a GaAs quantum well

Journal Article · Tue Nov 15 04:00:00 EST 1994 · Physical Review, B: Condensed Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.50.15099· OSTI ID:6995537

Kim, J C; Wake, D R; Wolfe, J P ^[1]

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1. Physics Department and Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)

Photoluminescence from GaAs quantum wells displays sharp spectral features associated with the free exciton. At high excitation density and low temperature, an additional component appears just below the lowest (heavy-hole) excitonic emission. Previous studies have attributed this feature to the biexciton, consisting of two electrons and two holes, because it appears below the exciton line and grows superlinearly with respect to the exciton intensity. In this paper, we considerably strengthen this identification by analyzing time- and space-resolved photoluminescence data that imply a dynamic chemical equilibrium between the excitons and biexcitons, i.e., a law of mass action. This thermodynamic (complementary to spectroscopic) evidence for biexcitons is based on the interdependent temporal decay and spatial transport behavior of the two components on a picosecond time scale. As the excitons recombine, the law of mass action describes the equilibrium over more than two orders of magnitude in exciton density as determined from the measured photoluminescence intensity and volume of the exciton gas.

• DOE Contract Number: AC02-76ER01198
• OSTI ID: 6995537
• Journal Information: Physical Review, B: Condensed Matter; (United States), Journal Name: Physical Review, B: Condensed Matter; (United States) Vol. 50:20; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360606* -- Other Materials-- Physical Properties-- (1992-)
ARSENIC COMPOUNDS
ARSENIDES
COUPLING
ELECTRON-HOLE COUPLING
EXCITONS
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
LUMINESCENCE
PHOTOLUMINESCENCE
PHYSICAL PROPERTIES
PNICTIDES
QUASI PARTICLES
RECOMBINATION
THERMODYNAMIC PROPERTIES