Spatially resolved detection of plasmon‐enhanced fluorescence using scanning tunneling microscopy

STM-induced light emission from thin films of perylene derivatives on the HOPG and Au substrates

“…In general, the wavelength of the emission by TIP strongly depends on both the material and shape of the metal tip/substrate. In our case, the resonance wavelength of TIP characterized by the Pt/Ir tip and Au substrate was located in the wavelength range of 700-1000 nm [ 26 ]. We clearly showed that TIP selectively enhances emission peaks related to vibronic transitions that are energy-matched to the resonance wavelength of TIP.…”

Luminescence experiments on supported molecules with the scanning tunneling microscope

“…For one-particle processes, luminescence corresponding to a transition between molecular levels is expected only for bias voltages exceeding the gap value. However, the observation of molecular luminescence at energies higher than the applied voltage has been reported for phthalocyanine [45,177] and porphyrin [46,52] molecules. The up-conversion luminescence observed for phthalocyanine has been interpreted as originating from a triplet-triplet annihilation process [45,177].…”

“…However, the observation of molecular luminescence at energies higher than the applied voltage has been reported for phthalocyanine [45,177] and porphyrin [46,52] molecules. The up-conversion luminescence observed for phthalocyanine has been interpreted as originating from a triplet-triplet annihilation process [45,177]. For the data reported by Liu et al, the energy forbidden light emission was tentatively interpreted as a two-electron process, similar to the mechanism proposed for sodium quantum well states [135], see Section 4.1.4.…”

Light emission from a double-decker molecule on a metal surface

“…The measured intensities, however, are not in conflict with previous reports of the emission of photons from molecules with hν > eV . 8,37,38 In summary, photon emission spectra from the nonplanar molecule NDIC may be understood from the field enhancement provided by the TIP mode of the STM junction. Inelastic tunneling to the vibrational progression of the affinity level causes the most intense spectral signature.…”