TY - JOUR

T1 - Fine structure splitting and biexciton binding energy in single self-assembled InAs/AlAs quantum dots

AU - Sarkar, D.

AU - van der Meulen, H. P.

AU - Calleja, J. M.

AU - Becker, J. M.

AU - Haug, R. J.

AU - Pierz, K.

N1 - Funding information: This work was partially supported by the Spanish MCYT (MAT2002-00139), the CAM (GR/MAT/ 0099/2004) and the European network “Collect” (HPRN-CT-2002-00291).

PY - 2006/5/1

Y1 - 2006/5/1

N2 - We report on photoluminescence investigations of individual InAs quantum dots embedded in an AlAs matrix which emit in the visible region, in contrast to the more traditional InAs/GaAs system. Biexciton binding energies, considerably larger than for InAs/GaAs dots, up to 9 meV are observed. The biexciton binding energy decreases with decreasing dot size, reflecting a possible crossover to an antibinding regime. Exciton and biexciton emission consists of linearly cross polarized doublets due to a large fine structure splitting up to 0.3 meV of the bright exciton state. With increasing exciton transition energy the fine structure splitting decreases down to zero at about 1.63 eV. Differences with InAs/GaAs QDs may be attributed to major dot shape anisotropy and/or larger confinement due to higher AlAs barriers.

AB - We report on photoluminescence investigations of individual InAs quantum dots embedded in an AlAs matrix which emit in the visible region, in contrast to the more traditional InAs/GaAs system. Biexciton binding energies, considerably larger than for InAs/GaAs dots, up to 9 meV are observed. The biexciton binding energy decreases with decreasing dot size, reflecting a possible crossover to an antibinding regime. Exciton and biexciton emission consists of linearly cross polarized doublets due to a large fine structure splitting up to 0.3 meV of the bright exciton state. With increasing exciton transition energy the fine structure splitting decreases down to zero at about 1.63 eV. Differences with InAs/GaAs QDs may be attributed to major dot shape anisotropy and/or larger confinement due to higher AlAs barriers.

KW - Biexcitons

KW - III-V semiconductors

KW - Photoluminescence

KW - Single quantum dots

UR - http://www.scopus.com/inward/record.url?scp=33646189006&partnerID=8YFLogxK

U2 - 10.1016/j.physe.2005.12.102

DO - 10.1016/j.physe.2005.12.102

M3 - Article

AN - SCOPUS:33646189006

VL - 32

SP - 111

EP - 114

JO - Physica E: Low-Dimensional Systems and Nanostructures

JF - Physica E: Low-Dimensional Systems and Nanostructures

SN - 1386-9477

IS - 1-2 SPEC. ISS.

ER -