Excitons and multi-excitons in single CdTe quantum dots probed by near-field spectroscopy

摘要: Abstract A near-field optical spectroscopy study of a single CdTe/ZnTe quantum dot at low temperatures is presented. While the photoluminescence spectrum excitation power reveals only one sharp peak due to radiative recombination excitons (X) in dot, several additional peaks appear with increasing density. The dominant features are ascribed exciton complexes and charged such as negatively (X−), neutral (2X 3X) negative (2X− 3X−) biexcitons triexcitons. Exciton charging arises efficient hole trapping by residual acceptors barrier material. This partly inhibits formation spectral feature appearing close X− tentatively assigned X2− excitons. found shift red power: two possible explanations for this unexpected behaviour proposed.