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

Recent achievements in controlling the electronic spectrum of InAs-based qu antum dots (QDs) formed by self-organization phenomena during the initial s tages of strained layer epitaxy are reviewed. Three different ways to exerc ise this control an discussed, based on variation of QD size with the amoun t of QD material deposited, tuning of the electronic levels in QDs by chang ing the matrix bandgap, and electronic coupling of neighbouring QDs vertica lly stacked in the growth direction. Possibilities to prevent thermal evapo ration of carriers out of QD states and to tune the emission wavelength in the range 0.85-1.3 mu m on GaAs substrates and up to 2 mu m on InP substrat es are demonstrated.