First-principles studies of carrier injection in polyethylene (PE) and ethylene-vinyl acetate copolymer (EVA) oligomers

摘要: First principles calculations are utilized in order to gain a better understanding of charge injection from metals insulators. As starting point, comparative study hole into polyethylene (PE) oligomer and ethylene-vinyl acetate (EVA) is conducted. We evaluate the barriers at metal/PE metal/EVA interfaces two ways: (1) band-plus-lineup based approach (2) density states analysis. In line with experimental findings that EVA much easier than PE, both methods indicated barrier smaller PE oligomer. The results showed vacuum level shift induced by adsorption on metal surface strongly affected molecular dipole varies over wide range (around 1 eV) depending orientation dipole. When points direction surface, ionization was shifted towards Fermi level, resulting decrease barrier. addition, it (mainly an anti-bonding combination C=O), which resides above may well serve as localized where holes can be injected.