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Title: Investigation of in-plane- and z-polarized intersubband transitions in pyramid-shaped InAs/GaAs quantum dots coupled to wetting layer: Size and shape matter

In this work, the effects of the shape and size on the intersubband electronic and optical properties of three-dimensional self-assembled pyramid-shaped InAs/GaAs quantum dots (QDs) were investigated in detail. More precisely, in-plane- and z-polarized transitions dipole moment (TDM), oscillator strength (OS), and absorption coefficients of P-to-S, WL-to-P, and WL-to-S transitions were studied as a function of the QD height. The P-to-S TDM showed to be strong and purely in-plane-polarized transition dominating two others. However, the TDMs and OSs of WL-to-P and WL-to-S transitions which are in-plane- and z-polarized transitions, respectively, showed a competition behavior for short and tall QDs. The former dominates for short QDs, and the latter for tall QDs. The physical reasons behind these interesting phenomena were also explained using the probability of finding the carriers in the pyramid region attached to the WL. The theoretical results are in good agreement with experimental data reported for short QDs [Appl. Phys. Lett. 82, 630 (2003)].
Authors:
;  [1]
  1. Physics Department, Faculty of Science, Shahid Chamran University of Ahvaz 61357-43135 (Iran, Islamic Republic of)
Publication Date:
OSTI Identifier:
22308508
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 4; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; ABSORPTION; CARRIERS; DIPOLE MOMENTS; GALLIUM ARSENIDES; INDIUM ARSENIDES; LAYERS; OPTICAL PROPERTIES; OSCILLATOR STRENGTHS; PROBABILITY; QUANTUM DOTS; THREE-DIMENSIONAL CALCULATIONS