Molecular-Resolution Interrogation of a Porphyrin Monolayer by Ultrahigh Vacuum Tip-Enhanced Raman and Fluorescence Spectroscopy

Naihao Chiang, Nan Jiang, Dhabih V. Chulhai, Eric A. Pozzi, Mark C. Hersam, Lasse Jensen, Tamar Seideman, Richard P. Van Duyne

Research output: Contribution to journalArticle

49 Citations (Scopus)


Tip-enhanced Raman scattering (TERS) and optically excited tip-enhanced fluorescence (TEF) of a self-assembled porphyrin monolayer on Ag(111) are studied using an ultrahigh vacuum scanning tunneling microscope (UHV-STM). Through selectively exciting different Q-bands of meso-tetrakis- (3,5-ditertiarybutylphenyl)-porphyrin (H2TBPP), chemical information regarding different vibronic excited states is revealed by a combination of theory and experiment; namely, TERS and time-dependent density functional theory (TDDFT) simulations. The observed TEF spectra suggest a weak coupling of H2TBPP to the substrate due to the bulky t-butyl groups and a possible alternative excited state decay path. This work demonstrates the potential of combining TERS and TEF for studying surface-mounted porphyins on substrates, thus providing insight into porphyrin-sensitized solar cells and catalysis. (Figure Presented).

Original languageEnglish
Pages (from-to)4114-4120
Number of pages7
JournalNano letters
Issue number6
Publication statusPublished - Jun 10 2015



  • time-dependent density functional theory (TDDFT)
  • tip-enhanced Raman spectroscopy (TERS)
  • tip-enhanced fluorescence (TEF)
  • ultrahigh vacuum scanning tunneling microscopy (UHV-STM)

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

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