自己形成的に分子線エピタキシャル成長したInAs/GaAs多重積層量子ドットからのエキシトン発光 Exciton Localization at the Vertically Stacked InAs/GaAs Quantum Dots Grown by Self-Assembled Molecular-Beam Epitaxy
This paper describes temperature effect on the exciton localization at vertically stacked InAs quantum dots (QDs). These QDs were grown on (100) -oriented GaAs by using the self-assembling growth mode in molecular beam epitaxy. Thermal quenching energy for the emission from the excitons localized at 5-stacked QDs was found to be8.5 meV, which was 3.5 times larger than the value for those at single-layered QDs. However, the QD size on upper layers of the stacked structure was revealed to become larger with the number of the stacking periods. By employing a size-controlled growth for the upper QDs, the thermal quenching energy was increased to13 meV. It is also shown that a post-annealing for the size-controlled QDs is effective to increase both the thermal quenching energy and the thermionic energy of the excitons. These effects are probably attributed to the reduction of nonradiative recombination centers and the improvement of dot-array uniformity in the stacked QD structure.
真空 42(8), 756-763, 1999-08-20
The Vacuum Society of Japan