Investigation of switching phenomenon of Se 75Te 25− xGa x amorphous system

Abstract

Thin film samples of different thicknesses ranging from 185 to 630 nm, were prepared from the synthesized amorphous Se 75Te 25− x Ga x (0 ≤ x ≤ 15 at.%) chalcogenide glass compositions by thermal evaporation technique. X-ray analysis showed that the amorphous nature of the obtained films. Investigations of the current–voltage ( I– V) characteristics of amorphous films are typical for a memory type switch. The conduction activation energy (Δ E σ ) was calculated from the temperature dependence of the sample resistance of the studied films in the temperature range (293–333 K) below the glass transition temperature. The mean value of the threshold switching voltage V ¯ t h increases linearly with increasing film thickness and decreases exponentially with temperature (below T g ) for all investigated compositions. The threshold voltage activation energy ɛ th was calculated from the temperature dependence of V ¯ t h of the studied films. The switching phenomenon observed in these films is explained in accordance with the electrothermal model for the switching process. The effect of Ga content on the studied parameters was also investigated.