STM-induced photon emission from sputter-deposited Ag nanoclusters

We present results on a scanning tunneling microscope (STM)-induced photon emission from nanoclusters formed in sputter-deposited silver (Ag) films, whose surface consists of Ag clusters ranging from 20 to 60 nm in diameter. The photon intensity images have been simultaneously obtained with the corresponding STM images. Those images show a good correlation between the topography and the intensity structure of photon emission. The intensity of photon emission exhibits an exponential-like increase with the increase of bias voltage. The photon emission spectra have separated peaks and exhibit a blue shift with the increase of bias voltage.