Comparison of the Strain-modified Band Gap Energies of Truncated and Untruncated InAs Quantum Dots in GaAs Matrix at Varying Inter-dot Spacings(Condensed Matter : Electronic Structure, Electrical, Magnetic and Optical Properties)

概要

論文の詳細を見る
The change in strain-modified band gap energies in truncated and untruncated InAs quantum dots (QDs) in the GaAs matrix has been comparatively investigated as a function of vertical inter-dot spacing, based on the strain-modified band lineups. The direct band gap energy is larger for truncated QDs at a given inter-dot spacing and shows more uniform band lineups in the truncated QD than in the untruncated counterpart, regardless of stacking distance. For both QD shapes, a narrower stacking increases the direct band gap energy. However, excessively close inter-dot spacing yields an indirect transition in which band gap decreases as dot spacing is narrowed further From the viewpoint of band lineups, for both QD shapes, a blueshift of emission energy with a closer inter-dot spacing is anticipated in a large dot spacing regime and a redshift in a small spacing regime. The experimental results in the literature, reporting either blueshift or redshift as the QDs are stacked closer, have been compared with the current results and discussed.
社団法人日本物理学会の論文
2004-12-15