UV-Photoelectron Spectroscopy of One- and Two Component Organic Crystals

Abstract

Abstract For potential applications of organic materials as active components In electronics, the energetic position of their valence and conduction levels are important parameters. For a given parent molecule, e.g. an aromatic hydrocarbon, the positions of these levels can be shifted substantially by attaching donor- or acceptor-type side group units. This will be demonstrated for the perylene skeleton in perylene-3,4,9,10-tetra-carboxylic-dianhydride. N,N′-diphenyl-perylene-3,4,9,10-tetracarboxylic-diimide, and diindeno[1,2,3.-c,d:1′,2′,3′-Imlperylene. Energy level manipulation by introducing donor: acceptor ground state interactions is another possible concept which has been checked with single crystals of the stoichiometric donor: acceptor complexes tetrathiafulvalene: p-chloranil, phenothiazine: tetracyanoquinodimethane. phenothazine: pyromellitic-dianhydride, perylene: pyromellitic-dianhydride and perylene: tetracyanoquinodimethane. where a certain dark conductivity or light-induced photoconductivity served to eliminate charging problems.