Transport mechanism in mica and SiO₂ dielectrics

Abstract

The current -voltage (I-V) characteristics in mica have been measured at different temperatures. The I-V characteristics possessed a temperature dependence, which was more clearly evident at lower fields. A comparison of the experimental results with the Frenkel thermo-emission theory and the theory of multiphonon-assisted tunnelling of charge carriers from the impurity centers, has been performed. It is shown that the experimental data better agree with the phonon-stimulated tunnelling theory than the Frenkel emission theory. Temperature-dependent I-V characteristics of М-SiO 2 -Si structures measured by Waters and Van Zeghbroeck [Appl. Phys. Lett. 76, 8, 1039 (2000)] are also reinterpreted in terms of the phonon-assisted tunnelling processes.

On a current mechanism in Ta2O5 thin films

“…Such behaviour of the lnI against 1/T dependences obtained in Ta 2 O 5 films can be explained by neither the FP nor Schottky mechanism because these mechanisms predict only a linear dependence of lnI on 1/T . Therefore, in order to explain the observed peculiarities of current dependence on temperature and applied voltage, the phonon-assisted tunnelling (PhAT) model, which was formerly used for describing similar data measured in some diodes [6,14,15], will be used.…”

“…Nevertheless, in a series of recently published works [10][11][12][13], the authors also point to Frenkel emission as the dominant mechanism of current in metal/Ta 2 O 5 /Si structures. Therefore, we want to show that in order to explain the temperature dependent I − V data measured for Ta 2 O 5 thin films, as well as for the ones of the other oxides [14], phonon-assisted tunnelling must be taken into account. This assertion will be proved by the analyses of our own data measured on metal/Ta 2 O 5 /Si structures and also data obtained by other investigators.…”

Comment on ‘Conductivity of single Mo6S9−xIxmolecular nanowire bundles’

“…In the present comment, we argue that such a behavior of temperature-dependent conductivity of Mo 6 S 9−x I x molecular nanowire bundles [1] can be more properly explained in the framework of the phonon-assisted tunneling model (PhAT), which has been used before for an explanation of temperaturefield-dependent conductivity in both inorganic and organic materials [2,3].…”

“…Here 2 = 8a( hω) 2 (2n + 1) is the width of the center absorption band, n = [exp( hω/k B T ) − 1] −1 , where hω is the phonon energy, ε T is the energetic depth of the center, e is the electronic charge unit, and a is the electron-phonon interaction constant (α = 2 0 /8( hω) 2 ). With the intention to ascertain the workability of the phonon-assisted model in the case of the conductivity of MSI, the comparison of experimental data extracted from figure 3(a) in [1] with the computed W (T ) curve is realized in figure 1.…”

Electronic transport mechanism in polydiacetylene crystals — variable range hopping or phonon-assisted tunnelling

“…, wherehω is the phonon energy, ε T is the energy depth of the center, e is the electron charge, and a is the electron-phonon interaction constant (a = Γ 2 0 /8(hω) 2 ).This relatively simple expression was proved to be valid to describe not only the temperature-dependent current-voltage data in inorganic materials [10], but also in the case of π-conjugated organic conducting polymers [6][7][8]. Consequently, we will use this equation to explain the peculiarities of temperature-dependent current in polydiacetylene single crystals.…”