Electrode area dependent switching behavior of Ge2Sb2Se4Te1 phase change material driven by narrow voltage pulse

Abstract

As a recently studied phase change material, Ge2Sb2Se4Te1 (GSST) shows excellent potential in the application of optical devices, because it presents very low loss in the amorphous state within the optical communication wavelength of 1550 nm and exhibits significant differences in optical properties before and after phase change. However, it is still challenging that, in real GSST devices, phase change switching is driven by narrow voltage pulse. In this study, the sandwich structures of GSST film with different electrode areas were prepared to analyze the phase change switching performance between crystalline and amorphous states. The results show that the endurance cycling of phase change switching increases with decreasing electrode area. When the electrode radius is 1 μm, the phase change switching number can reach 10 000. The improvement of this phase change switching can be attributed to the temperature uniformity, which was verified by the simulation of electrical pulse heating.