MOLECULAR LIGHT-EMISSION INDUCED BY INELASTIC ELECTRON-TUNNELING

Light emission from molecular layers has been induced by inelastically tunneling electrons in a tunneling junction. The fast quenching of mo lecular emission on metal surfaces was suppressed by use of the ''tran sparent conductor'' indium-tin-oxide for the junction electrodes. The emission measurements have been made in squeezable tunneling junctions as small as 10(-9) square centimeters, coated with 9-10 dichloro-anth racene layers. At a bias of 2.5 to 3.5 volts, yields of 5000 photons p er microcoulomb were observed. Evidence for the molecular origin of th e emission is given. This method shows good prospects for use in the i maging of chromophores on surfaces with atomic resolution.