Continuous wave and time resolved spectroscopy of InAsN/GaAsN based quantum dots

Abstract

We present a study of the optical properties of quantum dots based on a new family of semiconductors: III-V dilute nitrides such as (In,Ga)(N,As). Continuous wave and time resolved photoluminescence (PL) experiments allowed us to evaluate the impact of N incorporation during the growth of InAs/GaAs quantum dots. Previous work [V. Sallet et al., to be submitted to J. Cryst. Growth (2005); O. Schumann et al., J. Appl. Phys. 96, 2832 (2004)] showed that increasing the flux of N atoms into the growth chamber modifies drastically the size of the dots which leads to a bimodal growth. Two populations of dots with different sizes appear. The quantum dot PL line broadens and a second PL line appears at higher energy. Time resolved PL allows us to identify the nature of this second PL line: second population of quantum dots. A second decay time is observed which we interpret as being the consequence of the perturbation of the electronic states of the quantum dots. © 2005 WILEY-VCH Verlag GmbH & Co. KGaA,.