Near-Field Optical Spectroscopy of Individual Molecules in Solids
Phys. Rev. Lett., 73 (20):
2764-2767 (Nov 14, 1994)DOI: 10.1103/PhysRevLett.73.2764
Abstract
Near-field single-molecule spectroscopy was performed on a crystal of pentacene-doped p-terphenyl using an Al-coated optical fiber tip with 60 nm diam aperture as a near-field light source. Individual molecules located ≅400 nm from the tip had linewidths of 10-20 MHz at 1.8 K. The background fluorescence provided a useful distance-sensing signal, as it increased exponentially during approach with a characteristic length of ≅100 nm. Single molecules closest to the tip were identified by Stark shifts.