Quantum dot photodegradation due to CdSe-ZnO charge transfer: Transient absorption study

We study changes in ultrafast transient absorption due to photodegradation of quantum dots attached to ZnO nanowire. The time-resolved measurements reveal impact of photodegradation on three distinct kinetic components present in transient absorption tau similar to 7 ps, 80 ps, and 7.5 ns). In addition, we observe superlinear dependence of photodegradation rate on concentration of excited electrons. The data are used to evaluate the mean electron back-recombination time of similar to 1 mu s. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4729382]