Letter pubs.acs.org/JPCL
Ultrafast Charge Separation from Highly Reductive ZnTe/CdSe Type II Quantum Dots Shengye Jin,†,‡,∥ Jun Zhang,†,∥ Richard D. Schaller,†,§ Tijana Rajh,*,† and Gary P. Wiederrecht*,†,‡ †
Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States Argonne−Northwestern Solar Energy Research Center, Northwestern University, Evanston, Illinois 60208, United States § Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States ‡
S Supporting Information *
ABSTRACT: The low electron affinity of ZnTe quantum dots (QDs) makes it of interest for critically important photocatalytic processes. However, studies of charge transfer from such materials to adsorbates have not been reported. Here, the ultrafast internal and external charge separation dynamics in ZnTe/CdSe core/shell type II QDs have been studied through femtosecond transient absorption spectroscopy. The internal electron transfer time from a ZnTe core to a CdSe shell was found to be 0.67 ps, while the external electron transfer time from QDs to adsorbed molecules was found to be
