Femtosecond Pump-Probe Microspectroscopy of Single Perylene Nanoparticles.
J Phys Chem Lett
; 7(15): 2951-6, 2016 Aug 04.
Article
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| MEDLINE
| ID: mdl-27420175
ABSTRACT
We have developed a femtosecond pump-probe light scattering microspectroscopic system in which the output of a femtosecond Tisapphire oscillator (1 W, 82 MHz) was used as a light source; the pump light is the second harmonics (395 nm) of the laser output, and the probe light is a femtosecond white-light continuum (490-900 nm) generated with a photonic crystal fiber. Detection of the backscattered light from single nanoparticle on a glass substrate allowed us to obtain higher gain of the transient signals by â¼20 times in comparison with the conventional transmittance-mode experiment. This high-sensitivity of the backscattering detection makes it possible to examine ultrafast relaxation dynamics of excited states in organic nanoparticles, which, in general, are lower photodurability than the inorganic one. We applied the system to single nanocrystals of α-form perylene and then succeeded in direct observation of the excimer formation dynamics on a picosecond time scale. Single nanoparticle measurements for the perylene nanocrystals having a size range of 100 to 500 nm suggested that the excimer formation time became short from 2 ps to <0.3 ps for decreasing of the size.
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MEDLINE
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En
Revista:
J Phys Chem Lett
Año:
2016
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Article
País de afiliación:
Japón