Apertureless near-field distance-dependent lifetime imaging and spectroscopy of semiconductor nanocrystals

Eyal Yoskovitz, Dan Oron, Itzhak Shweky, Uri Banin

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

Apertureless near-field scanning optical microscopy, along with time-resolving capabilities, is used to produce optical imaging and spectroscopy measurements of single-semiconductor nanocrystals, in correlation with the AFM topography scan. The strongly distance-dependent energy transfer between the excited particle and silicon or metallic-coated AFM tips provides a contrast mechanism for subdiffraction-limited optical imaging. Fluorescence lifetime optical images show excellent contrast, sharpness, sensitivity, and resolution equivalent to that of the AFM topography images (sub 20 nm) and significantly improved over fluorescence intensity images. The sharper resolution of lifetime images is consistent with model predictions of energy transfer between an emitting dipole and a dielectric surface. Lifetime images also enable resolving multiple emitters located in the excitation spot. The comprehensive time and distance dependent data is used to study the imaging mechanism and the properties of silicon tips and platinum-coated tips as energy acceptors and quenchers. The findings provide a basis for use of lifetime imaging, in conjunction with apertureless near field microscopy, for simultaneous high-resolution topography and optical imaging.

Original languageEnglish
Pages (from-to)16306-16311
Number of pages6
JournalJournal of Physical Chemistry C
Volume112
Issue number42
DOIs
Publication statusPublished - Oct 23 2008

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

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