Plasmon-induced fluorescence and electroluminescence from porphine molecules on GaAs(110) in a scanning tunneling microscope

Abstract

Surface plasmon polaritons of the tip of a scanning tunneling microscope are used to induce fluorescence from (5,10,15,20)-tetraphenyl-21 H,23 H-porphine molecules on GaAs(110) surfaces at very low coverages. Fluorescence spectra exhibiting vibrationally resolved Q-band transitions show that the luminescence is of molecular origin. The emission is not directly induced by the tunneling current. Rather, radiationless energy transfer from plasmon modes of the tip leads to molecular excitation. © 2012 American Institute of Physics.