Photothermal Detection and Absorption Spectroscopy of Individual Nano-Objects
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Date: 05-17-2006
Start Time:
4:00pm
End Time: 5:00pm
Speaker: Stephane Berciaud
From:
Centre de Physique Moléculaire Optique et Hertzienne
Location: Interschool Lab, 7th floor, Schapiro/CEPSR
Hosted by:
Center for Integrated Science
Abstract:
We introduce Photothermal Heterodyne Imaging, allowing the optical detection and absorption spectroscopy of individual nano-objects. Surface Plasmon Resonance spectra of individual gold nanoparticles as small as 5nm are recorded. Intrinsic size effects are unambiguously observed and analyzed within the frame of Mie theory. Photothermal detection and spectroscopy of individual CdSe nanocrystals in the multiexcitonic regime are performed. The origin of the photothermal signal is discussed. For a same nanocrystal, absorption and luminescence spectra are confronted.