Surface states and negative electron affinity in polyethylene.
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.
Righi
M C
MC
International School for Advanced Studies (SISSA) and Istituto Nazionale per la Fisica della Materia, Via Beirut 4, I-34014 Trieste, Italy.
Scandolo
S
S
Serra
S
S
Iarlori
S
S
Tosatti
E
E
Santoro
G
G