Direct interface states observation by total-current spectroscopy

Interface electronic states resulting from interaction between Cu(1 1 1) surface and naphtalene-1,4,5,8-tetracarboxylic dianhydride (NTCDA) and N,N′-dibenzyl-naphtalene-tetracarboxylic diimide was investigated using the total-current spectroscopy. The evolution of these states with the film thickness increasing was observed directly upon the film growth. The contribution of different parts of the molecules into the formation of particular interface states was clarified.