Eur. Phys. J. B 27, 75-78 (2002)
https://doi.org/10.1140/epjb/e20020131

Influence of intrinsic internal field on recombination kinetics of high coverage (N11) InAs/GaAs quantum dots

¹ Istituto Nazionale per la Fisica della Materia and Dipartimento di Scienza dei Materiali, Universitá di Milano Bicocca, Via Cozzi 53, 20125 Milano, Italy
² European Laboratory for Non–linear Spectroscopy, Universitá di Firenze, Via N. Carrara 1, 50019 Sesto Fiorentino, Italy
³ School of Physics and Astronomy, University of Nottingham, University Park, Nottingham NG7 2RD, UK

Corresponding author: ^a stefano.sanguinetti@mater.unimib.it

Received: 25 October 2001
Revised: 5 February 2002
Published online: 15 May 2002

Abstract

We present, by means of cw and time–resolved photoluminescnce, a detailed experimental study of the optical properties of a large set of InAs self–assembled quantum dots grown on (N11)A/B GaAs substrates with different InAs coverages. Large variation of the external PL efficiency is observed, with a strong asymmetry between the A and B substrate termination. The analysis of PL time evolution leads us to exclude that the reduction of PL intensity would be associated to an increase of the non radiative recombination rates. The PL efficiency and decay times of the complete series of samples can be understood as a consequence of a large built-in electric potential associated to piezoelectric field and permanent dipole moment inside the QDs.