Type-II quantum dots in magnetic fields: excitonic behaviour

We calculated the ground state properties of an exciton in a type-II quantum dot in the presence of a perpendicular magnetic field. The dot is modelled by a quantum disk and we consider a type-II system, where the electron is confined in the disk, and the hole is located in the barrier material. In the first part, strain is neglected. The position of the hole and the magnetic field behaviour of the exciton are investigated as function of the disk radius R and thickness d. When strain is included, we show that strain can induce a type-I to type-II transition for the heavy hole and that the magnetic field is able to induce a heavy-to-light hole transition. (C) 2003 Published by Elsevier Science Ltd.