Abstract
The photon emission induced by STM on the vicinal Cu3Au(1,1,13) surface is found to present a yield comparable to pure Au. The control of the chemical ordering process permits to obtain ordered phases with a surface exhibiting either a paired-stepped structure with mixed Cu-Au terraces over a pure Cu atomic plane or a facetted structure. The STM-induced luminescence intensity of both surface types presents a high contrast between terraces and step edges. The photon emission efficiency is strongly correlated with the local barrier height, itself being influenced by local chemical characteristics and step distribution.