Quantum mechanical study of charge injection at the interface of polyethylene and platinum

Abstract

Charge injection at a polyethylene/platinum interface is studied through use of density functional theory (DFT). Various crystal orientations at the interface heterostructure are considered. The computed minimum barriers for electrons and hole injection at an impurity free interface are 3.15 and 2.62 eV, respectively. The work demonstrates that chemical impurities play an important role in the injection process. Impurity states, such as those of carbonyl, can reduce the effective barriers to charge injection to about 1.0 eV.

Communication: Band bending at the interface in polyethylene-MgO nanocomposite dielectric

“…2,3 However, deep traps also enhance charge injection which could lead to a higher conductivity. 4 Thus, trapping phenomena are of significant importance for electrical properties of dielectrics.…”

Influence of molecular additives on positive streamer propagation in ester liquids

“…If significant, this could be explained by the 1 s l electronic excitation energy which corresponds to an electronic state close to the Fermi level [7]. Electronic states close to the Fermi level is suggested to lower charge injection barriers between electrodes and dielectric material [17]. Thus, a low concentration of azobenzene could facilitate charge injection from the electrode leading to higher charge carr ier concentration in the liquid.…”

Effect of surface oxidation treatments on DC charge injection into polyethylene from aqueous electrolytes

“…Huzayyin et al calculated conduction band levels for crystalline polyethylene at a platinum interface [13]. The simulation revealed a localized depression of the conduction band level, such that the injection of electrons from platinum (work function of 5.6 eV) to polyethylene involved an energy barrier of 3.15 eV for impurity free polyethylene, which was decreased to less than 1 eV if carbonyl groups were present at the interface.…”

“…Both surface oxidation [14] and bulk oxidation [18] were found experimentally to increase the measured current through polyethylene with metallic contacts. Huzayyin et al calculated trap energies for carbonyl groups in polyethylene in the context of charge injection and bulk conduction [13,19].…”