Influence of molybdenum doping on the structural, electrical, and optical properties of germanium telluride thin films

Abstract

This study investigates the influence of molybdenum (Mo) doping on the local atomic structure, morphology, and electrical properties of amorphous germanium telluride (GeTe) thin films. Structural and morphological studies show that Mo-doping inhibits the crystallization of amorphous GeTe thin films. Moreover, the crystallization temperature of the GeTe thin film increases from 197 to 317 °C with increasing Mo dopant concentration. The electrical properties of Mo-doped GeTe thin films are discussed in terms of the capacitance–voltage characteristics in temperatures range 27–357 °C. The optical bandgap values decrease from 0.67 to 0.55 eV when increasing Mo doping in GeTe thin film. Mo integration significantly impacts the Ge–Te bond lengths and structural symmetry, increasing the degree of disorder in amorphous GeTe thin films. This study demonstrates the effectiveness of Mo doping in enhancing the thermal stability of the amorphous phase of GeTe for its envisioned memory and brain-inspired computing applications.

Keywords

• Phase change materials
• Magnetron sputtering
• Transmission electron microscopy
• Capacitance–voltage characteristics
• Raman spectroscopy
• Thermal stability