Ultrafast Transient Absorption Spectroscopy Investigations of Excited State Dynamics in SWNT/Polymer Composites

2004 ◽  
Vol 858 ◽  
Author(s):  
David J. Styers-Barnett ◽  
Steven P. Ellison ◽  
Cheol Park ◽  
Kristopher E. Wise ◽  
John M. Papanikolas
Keyword(s):  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Hot Electron ◽  
Plasmon Band ◽  
Near Ir ◽  
Spectral Shifts ◽  
Femtosecond Transient Absorption ◽  
Transient Spectra ◽  
Walled Carbon Nanotubes

ABSTRACTWavelength-resolved femtosecond transient absorption spectroscopy is used to follow the electronic dynamics of single-walled carbon nanotubes in polymers following visible and near IR photoexcitation. Electron-hole (e-h) pairs give rise to sharp features in the transient spectra that decay in amplitude and exhibit rapid spectral shifts. The decay reflects (e-h) recombination on both short (1.3 ps) and long (35 ps) time scales. Transient spectra also exhibit a broad photobleach at early times that arises from the cooling of a hot electron gas created via excitation at the red edge of a π-plasmon band.

Femtosecond Transient Absorption Spectroscopy of Single-Walled Carbon Nanotubes and their Ultrafast Optical Switching Behavior

2007 ◽  
Vol 121-123 ◽  
pp. 905-908 ◽  
Author(s):  
J.P. Yang ◽  
Manfred M. Kappes ◽  
H. Hippler ◽  
Andreas N. Unterreiner
Keyword(s):  
Absorption Spectroscopy ◽  
Optical Switching ◽  
Transient Absorption ◽  
Transient Absorption Spectroscopy ◽  
Switching Behavior ◽  
Ultrafast Optical ◽  
Decay Component ◽  
Femtosecond Transient Absorption ◽  
Pump And Probe ◽  
Walled Carbon Nanotubes

Two types of individualized single-walled nanotubes (SWNTs) in aqueous surfactant suspensions have been studied by femtosecond two-color absorption spectroscopy. A careful selection of pump and probe wavelengths allows for the determination of the “intrinsic” lifetimes of the lowest excited states which depend on the diameter of the SWNTs. Furthermore, a fast decay component in the ps to sub-ps regime was also observed and tentatively attributed to bundle relaxation. Likewise, this experimental approach can also assess spectral regions with decays faster than 1 ps, which is of great interest for all-optical switching devices near the optical telecommunication wavelength.

scholarly journals Ultrafast nonequilibrium dynamic process of separate electron and hole during exciton formation in few-layer tungsten disulfide

2021 ◽  
Author(s):  
Junjie Chen ◽  
Sen Guo ◽  
Dabin Lin ◽  
Zhaogang Nie ◽  
Chung-Che Huang ◽  
...  
Keyword(s):  
Absorption Spectroscopy ◽  
Dynamic Process ◽  
Formation Process ◽  
Transient Absorption ◽  
Tungsten Disulfide ◽  
Transient Absorption Spectroscopy ◽  
Femtosecond Transient Absorption ◽  
Nonequilibrium Dynamic ◽  
Femtosecond Transient Absorption Spectroscopy ◽  
Separate Electron

Femtosecond transient absorption spectroscopy has been employed to unravel separate initial nonequilibrium dynamic process of photo-injected electrons and holes during the formation process of the lowest excitons at the K-valley...

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