Photoluminescence Decay Time Measurements from Self-Organized InAs/GaAs Quantum Dots Grown on Misoriented Substrates.

摘要

Lately a lot of papers were devoted to the investigations of laser heterostructures based on quantum dots (QDs). This interest is based on the fact that QDs provide a zero-dimensional system with 3D carrier confinement resulting in atomic-like discrete electronic eigenstates. The delta-like state density preconditions the low theshold current densities of laser diodes and higher values of T(0) compared to existing semiconductor lasers. But the threshold current density of the classical QD laser diodes based on the single layer InAs heterostructures is far from predicted values. One of the possible obstacles to achieving the low threshold current density is low internal quantum efficiency in predicted by the theory excitation level range (10-100 A/cm2). The laser diode, which was made during this work, has a threshold current 110 A/cm2. The aim of this work is to study the mechanism limiting the quantum efficiency.