News & Events

When

Date - September 9, 2016
12:00 am

What

Associate Professor of Chemistry
UNC Charlotte

“Unraveling Trap State Fluorescence in Colloidal Quantum Dots”

Abstract:

Trap states in colloidal quantum dots are known to play an important role in exciton recombination dynamics. In this talk I will discuss some recent work on CdS, which is an interesting quantum dot system because it exhibits both exciton and trap photoluminescence (PL) at room temperature. Previous work has uncovered both electron and hole trapping processes, but the relationship between exciton and trap PL and the nature of the trap states remains poorly understood. Here I will describe a study on exciton and trap PL in several CdS samples. I will develop a detailed picture of recombination dynamics in these materials and, with the help of dynamical models, assign two distinct recombination pathways involving trapped electrons and holes. These results help us to understand the factors that govern charge carrier trapping in colloidal quantum dots and could help us to optimize their role in future applications.