Characterization of undoped and N–Ti codoped Zn₅Sb₃Te chalcogenides

Abstract

In this study, undoped Zn5Sb3Te (ZST) and N-Ti codoped ZST chalcogenides were investigated. The deposition rate of chalcogenides decreased when N and Ti were doped into ZST, caused by the low speed of reaction to form nitrides and the strong bond of Ti atoms, respectively. Surface roughness was significantly reduced to approximately one-seventh of the original value owing to the doping of N-Ti into ZST, implying high reliability. Based on X-ray diffraction and electrical measurements, the crystallization of ZST occurred after it was annealed at a high temperature between 250 ℃ and 300 ℃, while codoping N-Ti into ZST further increased the crystallization temperature to above 300 ℃. The crystallization temperature of N-Ti codoped ZST was approximately 150 ℃ higher than that of the conventional Ge2Sb2Te5 chalcogenide, indicating high thermal stability.