Electronic polarization at surfaces and thin films of organic molecular crystals: PTCDA

摘要

The electronic polarization energies, P = (P+) + (P-), of a PTCDA(perylenetetracarboxylic acid dianhydride) cation and anion in a crystallinethin film on a metallic substrate are computed and compared with measurementsof the PTCDA transport gap on gold and silver. Both experiments and theory showthat P is 500 meV larger in a PTCDA monolayer than in 50 A films. Electronicpolarization in systems with surfaces and interfaces are obtainedself-consistently in terms of charge redistribution within molecules.