Effects of Lattice Strain and Band Offset on Electron Transfer Rates in Type-II Nanorod Heterostructures.
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 (<200 fs), whereas curved NRHs with pronounced strain exhibit a longer charge-separation time of ∼700 fs.
†Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States.
Hunter
H
McDaniel
‡Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, United States.
Matthew
M
Pelton
†Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States.
Nuri
N
Oh
†Department of Materials Science and Engineering, University of Illinois, Urbana, Illinois 61801, United States.
Moonsub
M
Shim