CHARGED EXCITONS IN SELF-ASSEMBLED SEMICONDUCTOR QUANTUM DOTS

Interband excitations of an ensemble of InAs self-assembled quantum do ts have been directly observed in transmission experiments. The dots a re embedded in a field-effect structure allowing us to load the dots e lectrically. We establish an exact correspondence between Coulomb bloc kade in the device's vertical transport properties and Pauli blocking in the transmission spectra. We observe substantial shifts, up to 20 m eV, in the energies of the higher excitations on occupation of the ele ctron ground state. We argue that this is a consequence of an exciton- electron interaction.