Ballistic emission spectroscopy and imaging of a buried metal-organic   interface
  The silver-p-phenylene (Ag-PPP) interface is investigated using ballistic electron emission microscopy (BEEM). Multiple injection barriers and spatial nonuniformity of carrier injection over nanometer length scales are observed. No unique injection barrier is found. Physical reasons for these features are discussed. BEEM current images and the surface topography of the silver film are uncorrelated. 
Cedric Troadec, Linda Kunardi, and N. Chandrasekhar