The influence of post-growth annealing on the optical properties of InAs quantum dot chains grown on pre-patterned GaAs(100).

Optoelectronics Research Centre, Tampere University of Technology, PO Box 692, FIN-33101 Tampere, Finland.
Nanotechnology (Impact Factor: 3.84). 03/2012; 23(11):115702. DOI: 10.1088/0957-4484/23/11/115702
Source: PubMed

ABSTRACT We report on the effect of post-growth thermal annealing of [011]- ,[011(-)]-, and [010]-oriented quantum dot chains grown by molecular beam epitaxy on GaAs(100) substrates patterned by UV-nanoimprint lithography. We show that the quantum dot chains experience a blueshift of the photoluminescence energy, spectral narrowing, and a reduction of the intersubband energy separation during annealing. The photoluminescence blueshift is more rapid for the quantum dot chains than for self-assembled quantum dots that were used as a reference. Furthermore, we studied polarization resolved photoluminescence and observed that annealing reduces the intrinsic optical anisotropy of the quantum dot chains and the self-assembled quantum dots.