Modelling of quantum dot semiconductor devices

The goal of the project is to develop theoretical models that can be used to understand the properties of semiconductor optical devices based on quantum dot structures. Semiconductor quantum dots can be considered man-made artificial atoms, with a typical length scale of 100 Å, and it has long been speculated that, e.g., optical devices based on such nanostructures should offer superior characteristics in terms of controllability, power consumption and device speed. In recent years, it has been experimentally demonstrated that semiconductor lasers based on quantum dots offer record-low threshold current densities, but many aspects of quantum dot based devices are still not well understood.
The project initially consists in formulating models for calculating capture and escape rates in quantum dots; i.e., how fast can electrons be supplied to and removed from the tiny dots? These rates affect important device characteristics, such as the modulation speed of semiconductor lasers. Later stages of the project will involve setting up more macroscopic models for the overall device dynamics and comparison with experimental results obtained at COM.