MNP Seminar. 15 June 2016.

MNP seminar - David Binks. University of Manchester.

Ultrafast charge dynamics in Colloidal Quantum Dots

Colloidal quantum dots (CQDs) are nanometre-scale semiconductor crystals produced by solvent-based synthetic techniques. Quantum confinement of photo-generated carriers enables size-tuning of their absorption edge and photoluminescence, and has, coupled with their potential for scalable and low-cost production, motivated their investigation as the photo-absorbing or –emitting species in applications such as solar energy conversion, lighting and displays. However, the sub-nanosecond dynamics of photo-generated charges are often key to the performance of CQDs in these applications, determining the photoluminescence quantum yield and the efficiency of multiple exciton generation (MEG), for instance. In this seminar, our recent work on both the relationship between CQD structure and composition and the efficiency of MEG, and on ultrafast trapping by unsaturated surface atoms will be described.