Effects of Lattice Strain and Band Offset on ... - ACS Publications

Apr 12, 2012 - We use transient-absorption spectroscopy to investigate how the magnitude of band offset and lattice strain alters dynamics of photogen...
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Effects of Lattice Strain and Band Offset on Electron Transfer Rates in Type-II Nanorod Heterostructures Hunter McDaniel,*,†,§ Matthew Pelton,‡ Nuri Oh,† and Moonsub Shim*,† †

Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States



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ABSTRACT: Type-II nanorod heterostructures (NRHs) exhibit efficient directional charge separation and provide the potential to control this flow of charges through changes in structure and composition. We use transient-absorption spectroscopy to investigate how the magnitude of band offset and lattice strain alters dynamics of photogenerated electrons in CdSe/CdTe type-II NRHs. In the absence of alloying and strain effects, electron transfer occurs in ∼300 fs. Reducing the conduction band offset by means of alloying leads to an even shorter charge-separation time (