Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: Meyer-Neldel rule

Sortuj według:

Ogranicz wyniki do:

Electrical conductivity in thin films fabricated from nanoparticles of a polymeric composite based on PEDOT

Rais D., Hain J., Pich A., Pochekailov S., Nešpůrek S., Adler H. J. P., Hamáček A., Řeboun J.

Materials Science Poland

2009

Vol. 27, No. 3

769--780

A comparative study of electrical properties of films fabricated from a series of polymeric core shell particles and microgels is presented. The core shell particles consist of spherical polystyrene core covered by electrically conductive poly[3,4-(ethylenedioxy)thiophene] (PEDOT). Microgels are composed of PEDOT grains embedded into crosslinked, electrically insulating polymer bodies. The electrical resistivity of the films changes from 12 G?ˇcm to 100 ?ˇcm; the value depends on the thickness of the shell cover and the type of oxidant used for PEDOT polymerization. Electrical conductivity in the films of core shell particles is thermally activated and obeys the inverse Meyer-Neldel rule, which indicates that the electrical conductivity is governed by a common transport mechanism. Electrical conductivity depends, among others, on the humidity in the surrounding environment. In films consisting of particles with a high PEDOT content (and thus high conductivity) the resistivity increases as the humidity increases. Conversely, when the films are formed from particles having a low PEDOT content, the humidity has a reverse effect. An explanation for this behaviour is proposed. The frequency dependences of ac conductivities of high conductivity "core shell" and "microgel" films suggest existence of hopping charge carrier transport mechanism for large humidity scale.

Photoinduced degradation in the electrical properties of normally and obliquely deposited As2Se3 thin films

Bhardwaj P., Shishodia P. K., Mehra R. M.

Materials Science Poland

2007

Vol. 25, No. 1

69--77

Dark conductivity in As2Se3 films was measured in the temperature range 300-400 K. It was found to be of the doubly activated type in high- and low-temperature ranges. The experimental results were analysed using the Meyer-Neldel rule. The effect of light soaking on the electrical transport properties of normally and obliquely deposited As2Se3 thin films were examined. It has been observed that light soaking results in the degradation of photocurrent, which nearly saturates in an hour. Dark conductivity is fqund to be smaller after light soaking than without it.

Energy concepts involved in MOS characterization

Engström O., Gutt T., Przewłocki H. M.

Journal of Telecommunications and Information Technology

2007

nr 2

86-91

Starting from a quantum statistical reasoning, it is demonstrated that entropy properties of silicon/silicon dioxide interface electron traps may have a strong influence on measured distributions of interface states, depending on measurement method used. For methods, where the Fermi-level is used as a probe to define an energy position, the scale is based on free energy. On the other hand, methods based on thermal activation of electrons give the distribution on an enthalpy scale. It is shown that measured interface state distributions are influenced by the distribution of entropy, and that common features of measured energy distributions may be influenced by entropy variations. These results are used to interpret experimental data on the energy distribution of electron capture cross sections with an exponential increase followed by a more or less constant value as the energy distance of the traps from the conduction band edge increases. Such a relation is shown to be consistent with a situation where the emission and capture processes of electrons obey the Meyer-Neldel rule.