Power factor investigation of RF magnetron sputtered c-GeSbTe thin film

Germanium antimony tellurium (GeSbTe) thin film has been deposited by the RF magnetron sputtering from the initial material target of the 1:1:1 atomic ratio. The GeSbTe thin film was annealed by furnace at 473 K, 523 K, 573 K and 623 K samples for 1 h under ultra-high vacuum. The samples were analyzed by X-ray diffraction (XRD), field-emission scanning electron microscopy (SEM), and energy dispersive spectroscopy (EDS) to study their structure and chemical composition. The carrier concentration, charge mobility, electrical, Seebeck coefficient and power factor are reported. The as-deposited thin film showed amorphous and consequently cubic structure (c-GeSbTe) after annealing treatments. In addition, the film thickness was rapidly decreased with increasing annealing temperature. The as-deposited thin film had the atomic ratio of 1:0.6:0.7, and after annealing treatments became 1:0.9:0.9. The c-GeSbTe thin film annealed at 523 K showed the highest mobility, lowest electrical resistivity, and the highest power factor of 8.31 cm2 V− 1 s− 1, 3.25 × 10− 5 Ω m, and 0.81 × 10− 4 W m− 1 K− 2, respectively.