Eur. Phys. J. Plus (2020) 135: 203
https://doi.org/10.1140/epjp/s13360-019-00003-4

Regular Article

Nonlinear optical characteristics of an exciton in a GaSb-capped InSb heterodot: role of size control

¹ Physics Department, Faculty of Sciences, Laboratoire de Physique des Matériaux et Modélisation des Systèmes, (LP2MS), Unité Associée au CNRST-URAC 08, University of Moulay Ismail, B.P. 11201, Meknes, Morocco
² Max-Planck-Institut für Physik Complexer Systeme, Nöthnitzer Str. 38, 01187, Dresden, Germany
³ Condensed Matter Theory Group, Department of Physics and Astronomy, Uppsala University, 75120, Uppsala, Sweden

^* e-mail: a.ainane@fs-umi.ac.ma

Received: 6 July 2019
Accepted: 31 August 2019
Published online: 3 February 2020

Abstract

The optical characteristics of a bound electron-hole quasiparticle inside a GaSb-capped InSb nanodot were investigated using a combination between a density-matrix approach and variational calculations. Our theoretical model considers the electric permittivity mismatch between the core and shell materials via the self-energy term obtained by the means of an image charge approach. Furthermore, the core-to-shell conduction and valence band offsets were modeled by finite-depth confinement potentials. To elucidate the impact of the nanoheterodot spatial parameters on the confined exciton optical properties, we have investigated the change of the refractive index, the optical absorption coefficient, and the 1p–1s exciton transition energy with respect to the nanodot shape. Our numerical results exhibit the great potential for the improvement of the exciton optical properties by tailoring the nanodot size. It was also obtained that, for a fixed core radius, the resonance peak position of the optical absorption coefficient was still constant after a certain shell thickness value. Otherwise, decreasing the shell thickness leads to blue-shifting the 1p–1s transition energy.