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Updated: Jun 1, 2026
11:33
All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
Measuring electron and hole transfer in core/shell nanoheterostructures
Chi-Hung Chuang1, Tennyson L Doane, Shun S Lo
1Center for Chemical Dynamics and Nanomaterials Research, Department of Chemistry, Case Western Reserve University, 10900 Euclid Avenue, Cleveland, Ohio 44106, USA.
ACS Nano
|June 16, 2011
Summary
Ultrafast electron and hole transfer in CdTe/CdSe nanocrystals creates a shared charge transfer state. Subsequent relaxation shows vastly different timescales for electrons and holes, indicating Marcus inverted region dynamics.
Area of Science:
- Materials Science
- Nanotechnology
- Quantum Chemistry
Background:
- Quasi-type-II heterostructured nanocrystals offer unique optoelectronic properties.
- Understanding charge carrier dynamics is crucial for advanced nanomaterial applications.
Purpose of the Study:
- To investigate electron versus hole dynamics in photoexcited CdTe/CdSe nanocrystals.
- To elucidate charge transfer mechanisms across the core/shell interface.
Main Methods:
- Femtosecond transient absorption spectroscopy.
- Time-resolved photoluminescence spectroscopy.
- Selective excitation of core and shell states.
Main Results:
- Identical long-lived charge transfer states observed for both core- and shell-excited nanocrystals.
- Subpicosecond transfer rates for both electrons and holes across the interface.
- Significantly different relaxation rates: holes (τ(dec) ∼ 800 ps) and electrons (τ(avg) ∼ 8 ps).
- Electron transfer identified in the Marcus inverted region.
Conclusions:
- Ultrafast charge transfer leads to a common, long-lived state in CdTe/CdSe nanocrystals.
- The distinct relaxation dynamics highlight complex interfacial processes.
- Exciton-charge transfer state mixing and Marcus inverted region behavior are critical for analysis.
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