Light emission from Ag cluster films excited by conduction current

The light emission spectra obtained for a silver cluster film, excited by t he passage of electrical current through it, were measured by the charge-co upled device (CCD) combined with a monochromator in the spectral range 200/ 1050 nm (6.2/1.18 eV). This film is a two-dimensional ensemble of Ag cluste rs linked by tunneling on a dielectric substrate. It was shown that the lig ht emission spectra had a number of features, and the shape of spectrum dep ends on a voltage applied to the film. With increasing the voltage the spec trum starts to extend to high energies. The light emission in the visible s pectral region was observed already at 1 V applied to the film, i.e., the p hoton energy can exceed the excitation energy. It means that this phenomeno n is not trivial. In order to explain these results, an assumption about th e electron gas heating in metal clusters may be used.