Excitons dynamics in quantum dots

Excitonics confer to the quantum dots its interesting properties in devices. Because of the size-dependent nature of absorption spectra and the inability to produce homogeneous samples, obtaining a clear picture of the relaxation pathways in the dot has long remained a challenge. We have developed a state-resolved approach that employs tunable femtosecond pulses in which the pump and probe pulses are tuned into specific transitions in order to cleanly extract the dynamics of interest. This technique has yielded precise measurements of the electronic structural dynamics of quantum dots and has made inroads toward creating a unified picture of many of the key dynamic processes in these materials. Thanks to this technique, we could explore some properties of the dots such as optical gain, multi-excition, electron-phonon coupling and hot exciton cooling.

With the view of further enhancing the knowledge of fundamental relaxation dynamics and energy transfer in quantum dots, we are currently working with a 2DE setup.