Interdot carrier transfer in asymmetric bilayer InAs/GaAs quantum dot structures

Yu.I. Mazur, Zh.M. Wang, G.G. Tarasov, Min Xiao, and G.J. Salamo
Department of Physics, University of Arkansas, Fayetteville, Arkansas 72701

J.W. Tomm and V. Talalaev
Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Straße 2A, D-12489 Berlin, Germany

H. Kissel
Ferdinand-Braun-Institut für Höchstfrequenztechnik, Albert-Einstein-Straße 11, D-12489 Berlin, Germany

Published in:
Applied Physics Letters 86, 063102 (2005).
© 2005 American Institute of Physics. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the American Institute of Physics.

Abstract:
Transient photoluminescence from a series of asymmetric InAs quantum-dot bilayers with a GaAs barrier layer thickness varying from 30 to 60 monolayers between the quantum-dot planes is investigated. The interdot carrier transfer process is analyzed. In the framework of a three-level system, interdot carrier transfer times between 200 and 2500 ps are derived and compared with similar data from the literature. Within the semiclassical Wentzel-Kramers-Brillouin approximation, the observed "transfer time-barrier thickness-relation" supports nonresonant tunneling as the microscopic carrier transfer mechanism.

Full version in pdf-format.