Crystallinity-dependent volatile threshold switching properties of ZnTe thin films on epitaxial TiN electrodes

In this study, the structural and electrical properties of ZnTe thin films with volatile threshold switching (VTS) characteristics were investigated, focusing on the transition between polycrystalline and amorphous states. ZnTe films with distinct crystal orientations, including polycrystalline, (001), and (111) textures, were deposited on TiN bottom electrodes to systematically control their crystallinity under identical deposition conditions. Conductive atomic force microscopy measurements revealed improved microscopic homogeneity in the switching behavior with increasing amorphous characteristics of ZnTe. I–V measurements revealed that the amorphous ZnTe sample exhibited well-defined trap-limited conduction behavior, while the polycrystalline samples showed less distinct slope transitions, suggesting the possible involvement of alternative conduction paths, likely facilitated by grain boundaries. The findings of this study contribute to the development of optimized materials for energy-efficient and reliable selector devices, particularly for neuromorphic computing applications.