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All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics
Published on: January 19, 2018
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Single-Molecule Time-Resolved Spectroscopy in a Tunable STM Nanocavity.
Jiří Doležal1, Amandeep Sagwal1,2, Rodrigo Cezar de Campos Ferreira1
1Institute of Physics, Czech Academy of Sciences; Cukrovarnická 10/112, CZ16200 Praha 6, Czech Republic.
Nano Letters
|January 29, 2024
Summary
Single-molecule fluorescence lifetimes are reduced to picoseconds using scanning tunneling microscope nanocavities. This method precisely measures lifetimes, overcoming limitations of previous techniques for enhanced fluorescence yields.
Area of Science:
- Physical Chemistry
- Nanotechnology
- Spectroscopy
Background:
- Single-molecule emitters typically exhibit fluorescence lifetimes in the nanosecond range.
- Plasmonic nanostructures can significantly enhance fluorescence yields.
- Scanning tunneling microscopy (STM) tip-sample confinement forms a tunable nanocavity.
Purpose of the Study:
- To investigate the effect of STM-induced nanocavities on single-molecule fluorescence lifetimes.
- To directly measure excitation lifetimes of single-molecule emitters coupled to a nanocavity.
- To explore the relationship between coupling strength and fluorescence decay rates.
Main Methods:
- Time-resolved fluorescence decay measurements of single phthalocyanine molecules.
- Utilizing an STM setup to create a tunable tip-sample nanocavity.
- Decoupling molecules from metal substrates using ultrathin NaCl layers.
Main Results:
- Single-molecule fluorescence lifetimes were reduced to the picosecond range when coupled to the STM nanocavity.
- Ensembles of molecules without the nanocavity showed nanosecond-range lifetimes.
- Direct lifetime measurements overcame limitations of emission line width estimations.
Conclusions:
- STM-induced nanocavities dramatically alter single-molecule fluorescence dynamics.
- Picosecond lifetime measurements are achievable for single molecules in tailored nanocavities.
- This technique offers a precise method for studying molecule-nanostructure interactions.
