Please use this identifier to cite or link to this item:
|Title:||Atomic-scale structure and photoluminescence of InAs quantum dots in GaAs and AlAs|
Koenraad, P. M.
Wolter, J. H.
Maksym, P. A.
|Publisher:||American Physical Society|
|Citation:||Physical Review B, 2005, 72 (16), pp.165332.|
|Abstract:||We have determined the size, shape, and composition of InAs∕GaAs quantum dots (QDs) and InAs QDs embedded in an AlAs barrier by cross-sectional scanning tunneling microscopy. The outward relaxation and lattice constant of the cleaved surface of the QDs and their wetting layers were calculated using continuum elasticity theory and compared with experimental data in order to determine the indium concentration of the dots. Based on the structural results we have calculated the electronic ground states of the dots using a single band, effective mass approach. We find that the calculated ground state photoluminescence energy of the InAs∕GaAs dots is in excellent agreement with the measured energy. The observed large width of the PL spectrum of InAs∕AlAs dots can be attributed to Γ-Γ electron-hole recombination within an ensemble of dots with sizes varying between 2.4–4.2 nm in height and 10–20 nm along the base diagonal. We find that the electron-hole wave function overlap of small InAs∕AlAs QDs is 7.6 times larger than that of InAs∕GaAs QDs grown under the same conditions. This supports the explanation of the long decay times in InAs∕AlAs dots by an enhanced exciton exchange splitting.|
|Rights:||Copyright © 2005, American Physical Society. Deposited with reference to the publisher’s open access archiving policy.|
|Description:||This paper was published as Physical Review B, 2005, 72 (16), pp.165332. It is available from http://prb.aps.org/abstract/PRB/v72/i16/e165332. Doi: 10.1103/PhysRevB.72.165332|
|Appears in Collections:||Published Articles, Dept. of Physics and Astronomy|
Files in This Item:
|PhysRevB.72.165332.pdf||Published (publisher PDF)||531.89 kB||Adobe PDF||View/Open|
Items in LRA are protected by copyright, with all rights reserved, unless otherwise indicated.