A study on the influence of the cations and anions on the electrical conductivity in thin films of potassium and rubidium halides

Abstract

Thin films of rubidium chloride and rubidium iodide have been studied with respect to their transient and AC electrical behaviour at room temperature. The transient current was measured in the time range 10-5 s to 104 s, following the application of a step voltage for different amplitudes between 0.4 V and 2.0 V. The AC current was measured over the frequency range 1 Hz to 200 kHz for harmonically varying voltages with amplitudes in the range 0.4-1.2 V. Analysis of the results shows that the AC conductivity is due to anions, whereas the transient conductivity is due only to anions in the time interval from the onset of the applied step voltage up to 10-2 s. For times greater than 10-2 s the transient conductivity is due not only to anions, but also to the release of trapped electrons by the Poole-Frenkel mechanism alone or assisted by tunnelling. The results are compared with previous studies on potassium halides and rubidium bromide. Finally, the observed behaviour is correlated with the electronic polarizabilities of the ions and the effective charge of the salts.

Electrical properties of thin polyoxides grown at a low temperature using microwave oxygen plasma

“…At the lower field, the characteristics agree qualitatively with Frenkel-Poole nature which may be attributed to the presence of bulk oxide traps due to plasma damage. This type of mixed conduction mechanism has also been observed by other workers [12,13]. It is found that the leakage current and breakdown field of oxide on undoped poly are superior to the doped one.…”