Control of the emission wavelength of self-organized InGaAs quantum dots: main achievements and present status

Abstract

Recent achievements in controlling the electronic spectrum of InAs-based quantum dots (QDs) formed by self-organization phenomena during the initial stages of strained layer epitaxy are reviewed. Three different ways to exercise this control are discussed, based on variation of QD size with the amount of QD material deposited, tuning of the electronic levels in QDs by changing the matrix bandgap, and electronic coupling of neighbouring QDs vertically stacked in the growth direction. Possibilities to prevent thermal evaporation of carriers out of QD states and to tune the emission wavelength in the range 0.85-1.3 µm on GaAs substrates and up to 2 µm on InP substrates are demonstrated.