Carrier dynamics in energy states of InAs/GaAs quantum dots by measuring selective carrier filling and extracting techniques

In summary, the specification of energy levels and size dependence of energy level properties in InAs/GaAs quantum dots (QDs) were studied by using deep-level transient spectroscopy (DLTS) with very small pulse and varying the bias. It appears that the small sized InAs QDs have only one energy state with 121 meV below conduction band edge of GaAs barrier but the large sized QDs have several levels. Then, these total energy levels in QDs were specified. From the signal amplitudes, the population of carrier in single level could be estimated to be 1-2 electrons.