Study of the tuning of optical emission of InAs / GaAs quantum dots in the 1,3\'mü\'m and 1,5\'mü\'m regions

Author(s)

Marcelo Jacob da Silva

• Document type: Master's Dissertation
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Física (IF/SBI)
• Defense date: 1999-12-20
• Advisor: Alain Andre Quivy

Abstract

In this work, we studied the evolution of InAs quantum dots grown by MBE as a function o f the amount o f material deposited. The monitoring o f the quantum-dot prope1ties during their evolution was possible because of the growth of a sample in which the thickness o f material was varied continuously on its area. The structure o f the samples used in this work consists oftwo quantmn-dot layers, one on the samples\' surface and the other between GaAs barriers. The first quantum-dot layer was used in the morphological characterization, through AFM images, and the second one was probed by photoluminescense measurements. Moreover, the structure includes an InxGa1_xAs quantum well to be used as a reference. The possibility of carrying out optical and morphological measurements on the same sample provided us with a way to make comparisons between the topographical and optical features, yielding some interesting results, as the dependence of the optical emission with the surface quantum-dot coverage and its degradation when the islands density is higher than 1 ÜÜÜJ.Lm-2 (AU)