Optical polarization in columnar InAs/GaAs quantum dots: 8-Band k...p calculations

Toshio Saito, Hiroji Ebe, Yasuhiko Arakawa, Takaaki Kakitsuka, Mitsuru Sugawara

Research output: Contribution to journalArticle

48 Citations (Scopus)

Abstract

We have theoretically studied the optical polarization in columnar InAs/GaAs quantum dots (QDs), in which the self-assembled QDs are vertically stacked with no interdot spacing. The model structure of the columnar QDs consists of truncated-cone-shaped InAs QDs with the stacking-layer numbers (SLNs) of 1, 3, 5, 7, and 9. We used the valence-force-field model to calculate the strain distribution. We find that the biaxial strain in the middle layers of the columnar QDs decreases with increasing SLN and becomes negative for SLN=9. This is due to the condition that the vertical lattice constant of InAs in these layers has to match that of the side GaAs. By using the strain-dependent 8-band k...p theory for the electronic states, we calculated the transverse-electric (TE)- and transverse-magnetic (TM)-mode intensities for the electron-hole transitions. The piezoelectric effect is included in the calculations. For SLN=1 and 3, only the TE-mode transition occurs. With increasing SLN beyond 3, the TM-mode intensity increases while the TE-mode one decreases. Consequently, when SLN changes from 7 to 9, the dominant polarization character changes from the TE mode to the TM mode. This dominant polarization change is attributed to the increase of the light-hole character in the wave function of the ground hole state, which is the consequence of the negative biaxial strain in the middle layers for SLN=9. The change in the optical polarization calculated in this study is in good agreement with the photoluminescence experiment reported by Kita [Jpn. J. Appl. Phys., Part 2 41, L1143 (2002)].

Original languageEnglish
Article number195318
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume77
Issue number19
DOIs
Publication statusPublished - 2008 May 16
Externally publishedYes

Fingerprint

optical polarization
Light polarization
Semiconductor quantum dots
quantum dots
Polarization
Piezoelectricity
Electronic states
Wave functions
Electron transitions
Model structures
Lattice constants
Cones
Photoluminescence
indium arsenide
gallium arsenide
Electrons
strain distribution
polarization
field theory (physics)
cones

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

Cite this

Optical polarization in columnar InAs/GaAs quantum dots : 8-Band k...p calculations. / Saito, Toshio; Ebe, Hiroji; Arakawa, Yasuhiko; Kakitsuka, Takaaki; Sugawara, Mitsuru.

In: Physical Review B - Condensed Matter and Materials Physics, Vol. 77, No. 19, 195318, 16.05.2008.

Research output: Contribution to journalArticle

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