DC conduction in polymers under high electric fields

Abstract

The results of current–voltage (I–V) characteristics measured at different temperatures in polyethylene (PE) films obtained by our own experiments and the ones extracted from Suh K S et al (2000 J. Appl. Phys. 87 7333) are presented. The current depended strongly on temperature, namely, it increased with increase of temperature. The non-linearity in the I–V behaviour was observed at higher voltages. We suggest a phonon-assisted tunnelling model to explain the experimental results. The current mechanism in polymer diphenylaminostyrylbenzene (DASMB) films and in tris(8-hydroxyquinoline) aluminium (Alq3) films are also discussed.

Variable range hopping and/or phonon-assisted tunneling mechanism of electronic transport in polymers and carbon nanotubes

“…The object of the PhAT investigation has also been extensively studied in our and co-workers' papers: for polymers films [5,11,71], for MEH-PPV diodes [6], polyacetylene nanofibers [7], some oxide nanowires or films [8,10], carbon nanotube networks [12,13], graphene nanoribbons and graphene oxides [57], and polydiacetylene crystals [72]. Some authors have currently applied the PhAT model that we propose and Eq.…”

“…We explore the quantum-mechanical tunneling theory, in which the influence of phonons in the tunneling process is included [53]. For this purpose, we will employ the expression presented in [5,53], which is as follows for the tunneling rate from the centers of T energetic depth:…”

“…However, the focus of attention here was assigned to variable range hopping (VRH) [3,4] as the dominant transport mechanism in these materials, and the model is based only on the temperature dependences of conductivity. A number of articles have appeared in the last decade where the electrical-field induced phononassisted tunneling (PhAT) model has been suggested to describe the temperature dependent conductivity in polymers [5][6][7], inorganic materials [8][9][10][11] and carbon nanotubes [12,13]. The said PhAT model is based on the quantum-mechanical theory, and it can properly explain not only the temperature dependences of conductivity, but also the temperature-dependent current-voltage characteristics in a wide range of temperatures and electric field strengths.…”

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.…”

NonlinearI–Vcharacteristics in polyaniline due to phonon-assisted tunnelling

“…Very recently the phonon-assisted tunnelling model has been used for explanation of temperature-and fielddependent conductivity in some organic materials [11].…”