Electron-Hole Long-Range Exchange Interaction and Fine Structure of Excitonic Levels in Semiconductor Quantum Dots Dr. Serguei Goupalov ECE, Georgia Institute of Technology Electron-hole long-range exchange interaction is one of the main mechanisms responsible for the fine structure of excitonic levels in various QD systems. In bulk semiconductors it leads to the longitudinal-transverse splitting of exciton states which is on the order of 0.1 - 1 meV for A3B5 and A2B6 compounds. However, in QD systems with strong confinement, when the ratio of the bulk exciton Bohr radius to the QD size is much more than unity, the exchange interaction is enhanced with respect to its bulk value by a factor of the ratio in the third power. As a result, the exchange-induced splittings are on order of several tens of meV. In anisotropic QD systems with weak confinement, such as islands of QW width fluctuations, the long-range exchange interaction causes splittings of the exciton radiative levels to the states linearly polarized along the system principal axes. An insight to the phenomena will be provided by a comparison with an alternate treatment where the splittings are due to interaction of the exciton with the exciton-induced macroscopic longitudinal electric field.