Study of aluminium-modified Ge2Sb2Te5 thin films for the applicability as phase-change storage device material.

Electrical and optical studies have been carried out on aluminium-modified Ge2Sb2Te5 thin films to check its applicability as an active material in optical and electrical memory storage devices. Five polycrystalline bulk samples were prepared with compositions: Alx(Ge2Sb2Te5)1-x; x = 0, 0.08, 0.14, 0.21, 0.25. Amorphous thin films were deposited from the polycrystalline bulk by thermal evaporation. Temperature-dependent resistance shows the increase in crystallization temperature of Ge-Sb-Te films on aluminium addition. Activation energy for conduction, conductivity, optical band gap, coefficient of refraction and extinction coefficient are studied with respect to Al content in both amorphous and crystalline phases of Ge-Sb-Te alloy films. [ABSTRACT FROM AUTHOR]