Electrical and switching properties of the Se90Te10−xAgx (0⩽x⩽6) films

Amorphous Se90Te10−xAgx (0⩽x⩽6) films are obtained by thermal evaporation technique under vacuum from the synthesized bulk materials on pyrographite and glass substrates. X-ray analysis shows the amorphous nature of the obtained films. The dc electrical conductivity was studied for different thicknesses (165–711 nm) as a function of temperature in the range (298–323 K) below the corresponding Tg for the studied films. The obtained results show that the conduction activation energy has a single value through the investigated range of temperature which can be explained in accordance with Mott and Davis model. The I–V   characteristic curves for the film compositions are found to be typical for a memory switch. The mean value of the threshold voltage Vth¯ increases linearly with increasing film thickness (165–711 nm), while it decreases exponentially with increasing temperature in the investigated range for the studied compositions. The results are explained in accordance with the electrothermal model for the switching process. The effect of Ag on the studied parameters is also investigated.