The electronic polarization energies, P = (P+) + (P-), of a PTCDA (perylenetetracarboxylic acid dianhydride) cation and anion in a crystalline thin film on a metallic substrate are computed and compared with measurements of the PTCDA transport gap on gold and silver. Both experiments and theory show that P is 500 meV larger in a PTCDA monolayer than in 50 A films. Electronic polarization in systems with surfaces and interfaces are obtained self-consistently in terms of charge redistribution within molecules.
@article{arxiv.cond-mat/0205351,
title = {Electronic polarization at surfaces and thin films of organic molecular crystals: PTCDA},
author = {E. V. Tsiper and Z. G. Soos and W. Gao and A. Kahn},
journal= {arXiv preprint arXiv:cond-mat/0205351},
year = {2009}
}