Plasmon enhanced luminescence from fullerene molecules excited by local electron tunneling

Tunneling electrons from a scanning tunneling microscope (STM) induce luminescence from C-60 and C-70 molecules forming fullerene nanocrystals grown on ultrathin NaCl films on Au(111). Intramolecular. uorescence and phosphorescence associated with the transitions between the lowest electronic excited state and ground state of C-70 molecules are identified, leading to unambiguous chemical recognition on the nanoscale. Moreover we demonstrate that the molecular luminescence is selectively enhanced by localized surface plasmons in the STM tip-sample gap. (C) 2009 Optical Society of America