Files and links (1)
SubmittedOpen Access (License Unspecified), Open
Journal article
Distinguishing Electron and Hole Dynamics in Functionalized CdSe/CdS Core/Shell Quantum Dots Using Complementary Ultrafast Spectroscopies and Kinetic Modeling
Journal of physical chemistry. C, v 125(1), pp 31-41
14 Jan 2021
Abstract
The evolution of excitation energy and photo-generated charges in semiconductor quantum dots (QDs) functionalized with molecular acceptors can be probed on ultrafast time scales using techniques such as transient absorption (TA) spectroscopy. However, historical interpretations that the 1S(e-1S(3/2)(h) transition in Cd-chalcogenide QDs is fully attributable to electrons may be misleading, and multiexponential models used to fit TA kinetics do not correspond directly to specific photophysical processes. Here, we present visible-wavelength and mid-IR TA and time-resolved photoluminescence measurements to inform a comprehensive kinetic model of the photoexcited CdSe/CdS core/shell QDs functionalized with passivating oleic acid (OA), hole-accepting ferrocene, or electron-accepting naphthalene bisimide (NBI). We show that similar to 30% of the IS signal and 72% of the IR signal can originate from holes in well-passivated core/shell QDs. We also demonstrate evidence of electron trapping in OA-capped core/shell QDs, with additional electron transfer and hole trapping in the QDs functionalized with NBI. Electron (hole) trapping and detrapping occur in 450 +/- 100 ps (430 +/- 70 ps) and 340 +/- 100 ps (1.1 +/- 0.4 ns) respectively, while the time constant for electron transfer to NBI is similar to 1.8 ns. The comprehensive picture of photophysical processes provided by the complementary ultrafast techniques and kinetic modeling can accelerate both the fundamental science and application development of nanostructured and molecular systems.
Metrics
Details
- Title
- Distinguishing Electron and Hole Dynamics in Functionalized CdSe/CdS Core/Shell Quantum Dots Using Complementary Ultrafast Spectroscopies and Kinetic Modeling
- Creators
- Mohammad M. Taheri - Drexel UniversityKatherine C. Elbert - University of PennsylvaniaShengsong Yang - University of PennsylvaniaBenjamin T. Diroll - Argonne National LaboratoryJungmi Park - University of PennsylvaniaChristopher B. Murray - University of PennsylvaniaJason B. Baxter - Drexel University
- Publication Details
- Journal of physical chemistry. C, v 125(1), pp 31-41
- Publisher
- American Chemical Society; Washington, DC
- Number of pages
- 11
- Grant note
- CHE-1708991; CHE-1709827; DGE-1321851 / NSF; National Science Foundation (NSF) DE-AC02-06CH11357 / U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences; United States Department of Energy (DOE)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Chemical and Biological Engineering
- Web of Science ID
- WOS:000611410300004
- Scopus ID
- 2-s2.0-85100164635
- Other Identifier
- 991019168712904721
InCites Highlights
Data related to this publication, from InCites Benchmarking & Analytics tool:
- Collaboration types
- Domestic collaboration
- Web of Science research areas
- Chemistry, Physical
- Materials Science, Multidisciplinary
- Nanoscience & Nanotechnology