Laser excitation of surface-adsorbed molecules or nanostructures can be detected by a scanning tunneling microscope (STM) with near-atomic resolution. Single-molecule absorption spectroscopy detected by STM (SMA-STM) extends optical absorption techniques to imaging a single molecule on a surface. SMA-STM probes the molecule itself to detect absorption, instead of probing a reduction in the transmitted number of photons. Laser excitation provides energetic or temporal selectivity, while the STM spatially resolves the excitation at the submolecular level. Quantitative models are developed for the dependence of the absorption image on laser intensity and modulation and different systematic and random sources of noise in SMA-STM. It can also differentiate absorption sites within a single molecule.

Original languageEnglish (US)
Pages (from-to)48-49
Number of pages2
JournalMaterials Today
Issue number6
StatePublished - Jun 2007

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


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