Electron transfer from single quantum dot to individual acceptor molecules

ORAL

Abstract

The charge transfer rate from a single quantum dot to viologen molecules is studied by time-resolved photoluminescence measurements at the single-nanocrystal level. These hybrid structures are model systems for the understanding of the potential to serve as the basis of next-generation photovoltaic and photocatalytic devices. Previous ensemble measurements on quantum-dot / molecule complexes have been unable to directly resolve the charge-transfer rate from a quantum dot to a single molecule, because of the random distribution of the number of adsorbed molecules on each dot. By making measurements at the single-particle level, we are able to push the sensitivity of charge-transfer measurements down to the level of single acceptor molecules. For each QD measured, the electron-transfer rate is constant over time, and the photoluminescence blinking dynamics are independent of the measured transfer rate. The total electron-transfer rate is distributed in discrete, constant increments, corresponding to discrete numbers of adsorbed molecules on each QD. The measurement provides an optical method to count the number of active acceptor molecules bound to a single nanocrystal.

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Authors

  • Haixu Leng

    Univ of Maryland-Balt County

  • Shahab Derakhshan

    Drexel University, Univ of Delaware, Princeton University, Naval Surface Warfare Center\Carderock Division\West Bethesda site, Naval Surface Warfare Center and Georgetown Univ., Dept. of Physics and Astronomy, University of Delaware, Dept. of Physics and Astronomy, University of Deleware, Dept. of Physics and Astronomy, University of Nevada-Reno, university of Delaware, Contributors, Department of Physics, Astronomy and Geosciences, Towson University, Choice Research Group, Univ of the Sciences in Philadephia, Rutgers Univ, National Institute of Standards and Technology, Department of Chemistry, West Chester University, West Chester, PA 19383, Bucknell University, Towson University, University of Maryland, College of William and Mary, Naval Research Laboratory, Department of Physics, Villanova University, Department of Chemistry, Faculty of Medicine, University of Brescia, Department of Chemistry, State University of New York at Potsdam, Delaware State University DE, NIH Bethesda MD, Wilmington Friends School DE, University Of Rochester NY, Delaware State University, Department of Physics and Astronomy,West Virginia University, The National Energy Technology Laboratory, Non-tenure track professor at research institution, Government Sponsored Laboratory, Research and Development at Industrial Company, Tenure-track Professor at 4 yr college, Department of Physics and Astronomy and Department of Chemistry and Biochemistry, University of Delaware, Biology and Soft Matter Division, Oak Ridge National Laboratory, and Department of Physics and Astronomy, The University of Tennessee, Biology and Soft Matter Division, Oak Ridge National Laboratory, Lehigh Univ, Johns Hopkins Univ, NIST, GMU, GWU, Lock Haven University of PA, Univ of Maryland-Balt County; Center for Nanoscale Materials, Argonne National Laboratory, Department of Chemistry, Northwestern University, Univ of Maryland-Balt County, Pennsylvania State University, BAE Systems, Inc., Nashua, New Hampshire 03061, Department of Physics, West Virginia University, Morgantown, West Virginia, 26506-6315, California State University, Long Beach

  • Shahab Derakhshan

    Drexel University, Univ of Delaware, Princeton University, Naval Surface Warfare Center\Carderock Division\West Bethesda site, Naval Surface Warfare Center and Georgetown Univ., Dept. of Physics and Astronomy, University of Delaware, Dept. of Physics and Astronomy, University of Deleware, Dept. of Physics and Astronomy, University of Nevada-Reno, university of Delaware, Contributors, Department of Physics, Astronomy and Geosciences, Towson University, Choice Research Group, Univ of the Sciences in Philadephia, Rutgers Univ, National Institute of Standards and Technology, Department of Chemistry, West Chester University, West Chester, PA 19383, Bucknell University, Towson University, University of Maryland, College of William and Mary, Naval Research Laboratory, Department of Physics, Villanova University, Department of Chemistry, Faculty of Medicine, University of Brescia, Department of Chemistry, State University of New York at Potsdam, Delaware State University DE, NIH Bethesda MD, Wilmington Friends School DE, University Of Rochester NY, Delaware State University, Department of Physics and Astronomy,West Virginia University, The National Energy Technology Laboratory, Non-tenure track professor at research institution, Government Sponsored Laboratory, Research and Development at Industrial Company, Tenure-track Professor at 4 yr college, Department of Physics and Astronomy and Department of Chemistry and Biochemistry, University of Delaware, Biology and Soft Matter Division, Oak Ridge National Laboratory, and Department of Physics and Astronomy, The University of Tennessee, Biology and Soft Matter Division, Oak Ridge National Laboratory, Lehigh Univ, Johns Hopkins Univ, NIST, GMU, GWU, Lock Haven University of PA, Univ of Maryland-Balt County; Center for Nanoscale Materials, Argonne National Laboratory, Department of Chemistry, Northwestern University, Univ of Maryland-Balt County, Pennsylvania State University, BAE Systems, Inc., Nashua, New Hampshire 03061, Department of Physics, West Virginia University, Morgantown, West Virginia, 26506-6315, California State University, Long Beach

  • Shahab Derakhshan

    Drexel University, Univ of Delaware, Princeton University, Naval Surface Warfare Center\Carderock Division\West Bethesda site, Naval Surface Warfare Center and Georgetown Univ., Dept. of Physics and Astronomy, University of Delaware, Dept. of Physics and Astronomy, University of Deleware, Dept. of Physics and Astronomy, University of Nevada-Reno, university of Delaware, Contributors, Department of Physics, Astronomy and Geosciences, Towson University, Choice Research Group, Univ of the Sciences in Philadephia, Rutgers Univ, National Institute of Standards and Technology, Department of Chemistry, West Chester University, West Chester, PA 19383, Bucknell University, Towson University, University of Maryland, College of William and Mary, Naval Research Laboratory, Department of Physics, Villanova University, Department of Chemistry, Faculty of Medicine, University of Brescia, Department of Chemistry, State University of New York at Potsdam, Delaware State University DE, NIH Bethesda MD, Wilmington Friends School DE, University Of Rochester NY, Delaware State University, Department of Physics and Astronomy,West Virginia University, The National Energy Technology Laboratory, Non-tenure track professor at research institution, Government Sponsored Laboratory, Research and Development at Industrial Company, Tenure-track Professor at 4 yr college, Department of Physics and Astronomy and Department of Chemistry and Biochemistry, University of Delaware, Biology and Soft Matter Division, Oak Ridge National Laboratory, and Department of Physics and Astronomy, The University of Tennessee, Biology and Soft Matter Division, Oak Ridge National Laboratory, Lehigh Univ, Johns Hopkins Univ, NIST, GMU, GWU, Lock Haven University of PA, Univ of Maryland-Balt County; Center for Nanoscale Materials, Argonne National Laboratory, Department of Chemistry, Northwestern University, Univ of Maryland-Balt County, Pennsylvania State University, BAE Systems, Inc., Nashua, New Hampshire 03061, Department of Physics, West Virginia University, Morgantown, West Virginia, 26506-6315, California State University, Long Beach

  • Shahab Derakhshan

    Drexel University, Univ of Delaware, Princeton University, Naval Surface Warfare Center\Carderock Division\West Bethesda site, Naval Surface Warfare Center and Georgetown Univ., Dept. of Physics and Astronomy, University of Delaware, Dept. of Physics and Astronomy, University of Deleware, Dept. of Physics and Astronomy, University of Nevada-Reno, university of Delaware, Contributors, Department of Physics, Astronomy and Geosciences, Towson University, Choice Research Group, Univ of the Sciences in Philadephia, Rutgers Univ, National Institute of Standards and Technology, Department of Chemistry, West Chester University, West Chester, PA 19383, Bucknell University, Towson University, University of Maryland, College of William and Mary, Naval Research Laboratory, Department of Physics, Villanova University, Department of Chemistry, Faculty of Medicine, University of Brescia, Department of Chemistry, State University of New York at Potsdam, Delaware State University DE, NIH Bethesda MD, Wilmington Friends School DE, University Of Rochester NY, Delaware State University, Department of Physics and Astronomy,West Virginia University, The National Energy Technology Laboratory, Non-tenure track professor at research institution, Government Sponsored Laboratory, Research and Development at Industrial Company, Tenure-track Professor at 4 yr college, Department of Physics and Astronomy and Department of Chemistry and Biochemistry, University of Delaware, Biology and Soft Matter Division, Oak Ridge National Laboratory, and Department of Physics and Astronomy, The University of Tennessee, Biology and Soft Matter Division, Oak Ridge National Laboratory, Lehigh Univ, Johns Hopkins Univ, NIST, GMU, GWU, Lock Haven University of PA, Univ of Maryland-Balt County; Center for Nanoscale Materials, Argonne National Laboratory, Department of Chemistry, Northwestern University, Univ of Maryland-Balt County, Pennsylvania State University, BAE Systems, Inc., Nashua, New Hampshire 03061, Department of Physics, West Virginia University, Morgantown, West Virginia, 26506-6315, California State University, Long Beach