Structural phase contrast in polycrystalline organic semiconductor films observed by broadband near-field optical spectroscopy

Nano Lett. 2007 Apr;7(4):998-1002. doi: 10.1021/nl070083i. Epub 2007 Mar 27.

Abstract

We demonstrate a novel near-field absorption spectrometer with 100 nm spatial resolution based on an ultrabroadband Ti:sapphire oscillator coupled to an aperture NSOM, enabling the measurement of nanoscale absorption spectra. The instrument is particularly suited for structural phase-selective imaging of organic materials at the nanoscale. We demonstrate that variations in the local absorption spectrum allow us to distinguish between the crystalline and the amorphous phases in polycrystalline phtalocyanine films, thus providing previously unavailable information on their mesoscopic texture.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Crystallization / methods*
  • Macromolecular Substances / chemistry
  • Materials Testing
  • Membranes, Artificial*
  • Molecular Conformation
  • Nanostructures / chemistry*
  • Nanostructures / ultrastructure*
  • Nanotechnology / methods*
  • Organic Chemicals / chemistry*
  • Particle Size
  • Refractometry / methods*
  • Semiconductors*
  • Spectrum Analysis / methods*
  • Surface Properties

Substances

  • Macromolecular Substances
  • Membranes, Artificial
  • Organic Chemicals