Fine structure of the exciton in a single asymmetric CdTe quantum dot

• DOI: 10.1016/s0022-0248(00)00191-3
• Publication Date: 2002-07-25T10:55:22Z
• Authors: L Besombes; L Marsal; K Kheng; T Charvolin; Le Si Dang; A Wasiela; H Mariette
• Keywords: [PHYS]Physics [physics]; 0103 physical sciences; 01 natural sciences

Zero-dimensional excitons localized in CdTe/ZnTe nanostructures have been studied by spatially resolved magnetophotoluminescence spectroscopy. At zero magnetic field, exciton transitions present a doublet structure linearly polarized along two orthogonal directions. We attribute this doublet structure to bright exciton states |±1>split by the local asymmetry of the localization potential. With increasing magnetic field oriented along the growth axis, a mixing of dark exciton states |±2> and bright exciton states is observed for localization sites that present a large zero-field splitting. This allows a direct estimate of the electron and hole g-factors and of the isotropic exchange energy for strongly localized heavy-hole excitons.