Structural Optimization of Chalcogenide Thin Films for Enhancing the Threshold Switching Performance.

This study conducts a comprehensive investigation into the physical properties of germanium telluride (GeTe, GT) thin films and their associated electronic devices to establish fundamental relationships that are essential for achieving reliable threshold switching (TS) characteristics. Chemical composition variations in GT thin films significantly influence their crystallinity, atomic vibration modes, chemical binding status, bandgap, and distribution of electronic traps. The increase in the tellurium (Te) content results in elevated Urbach energy, subsequently reducing the effective bandgap energy. Excluding GT, trap energy increases proportionally with increasing Te content. Correlating electrical properties with physical characteristics reveals key conditions necessary for stable TS behavior: maintaining amorphous crystallinity, optimizing the chemical composition of the GT layer, and ensuring an appropriate bandgap and trap energy. These findings underscore the importance of precise chemical composition control for reliable TS performance. Insights from this study can guide nanoscale analyses of bonding structures in Te-based binary TS systems and present opportunities for material optimization across various applications.