We report computer simulations of an excess electron in various structural motifs of polyethylene at room temperature, including lamellar and interfacial regions between amorphous and lamellae, as well as nanometre-sized voids. Electronic properties such as density of states, mobility edges, and mobilities are computed on the different phases using a block Lanczos algorithm. Our results suggest that the electronic density of states for a heterogeneous material can be approximated by summing the single phase density of states weighted by their corresponding volume fractions. Additionally, a quantitative connection between the localized states of the excess electron and the local atomic structure is presented.The US National Science Foundation under grant CHE-0911635 and from his Stokes Professorship in Nano Biophysics from Science Foundation Ireland thanks the Irish Centre for High End Computing (ICHEC) for computer resources and Science Foundation Ireland for support from grant 08-IN.1-I1869

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A simulation model to investigate the statistical property of electrical breakdown is presented based on the field-assisted percolation model for dielectric breakdown, by expressing the disorder in morphology as randomly distributed trap barriers. The effects of sample area and large defects on the statistical property of breakdown are also studied, and the statistical behavior of the lifetime is investigated by considering the stochastic development of deteriorated regions. In addition an equation describing the breakdown probability in homogeneous materials is derived from percolation theory, which we show fits well to the simulation data. The breakdown probability is expressed in terms of trap distribution, and thus provides a way to connect the disorder in polymer morphology with the stochastic nature of breakdown.

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