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Thermionic, tunnelling, and polarization currents in zinc oxide varistors

1997; Elsevier BV; Volume: 17; Issue: 12 Linguagem: Inglês

10.1016/s0955-2219(96)00240-3

1873-619X

M.S. Castro, C. M. Aldao,

Transition Metal Oxide Nanomaterials

We report an analysis of time, voltage, and temperature dependencies for ZnO varistors conductance. The conduction mechanisms proposed to interpret experiments include thermionic, tunnelling, and polarization currents. We analyse here the contributions of these mechanisms to conduction in order to identify their roles. We conclude that a tunnelling current shows the correct trends in the current-temperature curve. Also, capacitance measurements as a function of time and temperature are presented to discuss the influence of interface and deep bulk traps.