title: Surface states and negative electron affinity in polyethylene.
abstract: First-principles calculations are used to investigate the electronic properties of the surfaces of polyethylene. The calculations support the experimental evidence of a negative electron affinity, with calculated values of -0.17 eV and -0.10 eV for surfaces with chains perpendicular and parallel to the surface normal, respectively. Both surfaces exhibit a surface state with binding energy -1.2 +/- 0.5 eV with respect to the bulk polyethylene conduction band minimum. Implications of these findings on spectroscopy, as well as on the transport and aging properties of polyethylene for high-voltage applications, are discussed.
authors.affiliation: International School for Advanced Studies (SISSA) and Istituto Nazionale per la Fisica della Materia, Via Beirut 4, I-34014 Trieste, Italy.
authors.forename: M C
authors.initials: MC
authors.lastname: Righi
authors.forename: S
authors.initials: S
authors.lastname: Scandolo
authors.forename: S
authors.initials: S
authors.lastname: Serra
authors.forename: S
authors.initials: S
authors.lastname: Iarlori
authors.forename: E
authors.initials: E
authors.lastname: Tosatti
authors.forename: G
authors.initials: G
authors.lastname: Santoro