Investigation of Switching and dc Conductivity on Some Vanadium Phosphate Tellurite Oxide Glasses

Abstract

Subject classification: 72.20. Ee; 72.80.Ga; 72.80.Ng; S10.15 The dc conductivity and switching properties of glassy samples of the system (76V 2 O 5 -24P 2 O 5 ) 1--x (TeO 2 ) x (where x = 0.0, 0.02 and 0.1 mol%) are investigated in the temperature range 303-625 K. The activation energy of conduction DE s , the predominant phonon frequency n ph and the Debye temperature q D were deduced. A composition dependence of the samples has been found. Thickness and temperature dependence of the I-V characteristics of the samples have been studied showing switching at the turnover point (TOP) from high resistance state (off state) to the negative differential resistance state (NDRS). Measurements of the dissipated power P th , the threshold voltage V th and the threshold resistance R th were carried out at TOP for different thicknesses and temperatures of the samples. The activation energies DE v , DE r and DE p (caused by threshold voltage, current and power, respectively) at the turnover point are deduced for different thicknesses of the samples. Temperature and composition dependence of the conduction path temperature (T 0 ), rise in temperature of conduction path DT J , specific heat S, density of localized states N(E F ) and the hopping distance have been obtained. The results are interpreted in terms of both electrothermal and the small polaron model.

Investigation of DC conductivity and switching phenomenon of Se80Te20−xGex amorphous system

“…9 as an example. It is observed thatP th increases with temperature in the investigated range, which agrees with results obtained before for other amorphous semiconductor materials [16,19]. This can be explained by the following equations:…”

“…As the electric field is applied, these dipoles tend to orient in the direction of the field. The orientation process depends on the viscosity of the amorphous matrix as well as the applied field [16]. As the temperature of the conduction path increases its viscosity decreases, which leads to an increase in the orientation processes up to threshold switching point.…”

Memory switching characteristics in amorphous ZnIn2Se4 thin films

“…This may be due to the fact that as the temperature increases, the number of random collisions as well as scattering between the charge carriers and the network atoms increases, leading to an increase in P th . 17 The value of DE P was deduced by least square fitting and is given in Table 1. difference of the breakdown (DT Breakdown ) obtained is given by 18…”