Minimum of oscillator strength of excitons in ultra-narrow GaAs/AlGaAs quantum wells: Theory and experiment
A theoretical and experimental study of the exciton in ultra-narrow quantum wells (QWs) is performed. A crossover from strong (separate localization of electron and hole levels) to weak confinement (with localization of excitonic center of mass) is predicted to occur for decreasing thickness, and is characterized by a minimum of the oscillator strength per unit area. Cathodoluminescence measurements performed on a series of GaAs/Al0.35Ga0.65As QWs with thicknesses from one to eight monolayers show a minimum of the oscillator strength, in agreement with theory, and indicate that the crossover from strong to weak confinement occurs at a thickness of about three monolayers for this composition. (C) 1998 Elsevier Science B.V. All rights reserved.
WOS:000075383500032
1998
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Univ Pavia, INFM, Dipartimento Fis A Volta, I-27100 Pavia, Italy. Univ Leipzig, Fak Phys & Chem, D-04103 Leipzig, Germany. Ecole Polytech Fed Lausanne, Inst Micro & Optoelect, CH-1015 Lausanne, Switzerland. Andreani, LC, Univ Pavia, INFM, Dipartimento Fis A Volta, Via Bassi 6, I-27100 Pavia, Italy. andreani@pv.infn.it
ISI Document Delivery No.: 110LT
Cited Reference Count: 15
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