Investigation of switching phenomenon of Se75Te25−xGax amorphous system

Thin film samples of different thicknesses ranging from 185 to 630 nm, were prepared from the synthesized amorphous Se75Te25−xGax (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 (ΔEσ) 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¯th increases linearly with increasing film thickness and decreases exponentially with temperature (below Tg) for all investigated compositions. The threshold voltage activation energy ɛth was calculated from the temperature dependence of V¯th 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.

► The switching phenomenon of a-Se75Te25−xGax (x = 0, 5, 10 and 15%) in thin film form of different thicknesses ranging from (185–630 nm).
► The current–voltage (I–V) characteristics at different temperature.
► The conduction activation energy, the threshold switching voltage and the threshold activation energy were calculated.
► The electrothermal model support the switching mechanism in the investigated compositions.