Photoluminescence study on the growth of self-assembled InAs quantum dots: Formation characteristics of bimodal-sized quantum dots

Abstract

We report a photoluminescence (PL) study on the growth process of self-assembled InAs quantum dots (QDs) under various growth conditions. Distinctive double-peak feature was observed in the PL spectra of the QD samples grown at the relatively high substrate temperature. From the excitation power-dependent PL and the temperature-dependent PL measurements, the double-peak feature is associated with the ground-state transitions from InAs QDs with two different size branches. In addition, the variation in the bimodal size distribution of the QD ensembles with different InAs coverage is demonstrated. (c) 2006 Elsevier B.V. All rights reserved.