Regensburg 2000 – wissenschaftliches Programm
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HL: Halbleiterphysik
HL 27: Poster II: SiC (1-7), Ultrakurzzeitdynamik (8-15), Halbleiterlaser (16-20), GaN (21-38), III-V Halbleiter (39-56), Photovoltaik (57-64), Störstellen (65-68), Tern
äre Halbleiter (69-70)
HL 27.10: Poster
Mittwoch, 29. März 2000, 14:00–19:00, A
Time resolved photoluminescence in GaAs/InGaP heterostructures — •C. Rudamas1, B. Al(e)n1, J. Martinez-Pastor1, A. Garcia-Crist(o)bal1, and L. González2 — 1Instituto de Ciencia de Materiales y Departamento de Física Aplicada, Universidad de Valencia, P.O. Box 2085, 46071 Valencia, Spain — 2Instituto de Microelectrónica de Madrid, CNM-CSIC, PTM, 28760 Tres Cantos, Madrid, Spain
The particular band alignment as well as the degree of disorder in the GaAs/InGaP system influence enormously the excitonic recombination dynamics. In this work the temporal behavior of the photoluminescence is investigated by time resolved luminiscence (TRPL) experiments. For quantum wells (QWs) thinner than 3.4 nm the decay time increases with decreasing thickness, whereas is practically constant for thicker QWs in the thickness range investigated experimentally. A quantitative account of this behavior gives that the dominant factor for relatively thin QWs, is the electron and holes wavefunction overlap integral, which is determined by the small conduction band offset in the system studied. As a consequence the 3D limit is rapidly reached even for relatively thick QWs, as compared to the case of the GaAs/AlGaAs system. A non-exponential decay as well as a decrease of the lifetime with raising temperature have been also observed. These results are discussed by considering excitons relaxing in a random potential.