The resistance as a function of temperature (R–T) was measured using the in situ measurement with a heating rate of 30 °C/min. The sample temperature was measured by a Pt-100 thermocouple located at a heating stage controlled by a TP 94 temperature controller (Linkam Scientific Instruments Ltd, Surrey, UK). The optical band gap was measured by NIR spectrophotometer. The phase structures of the films annealed at various temperatures were investigated by XRD analysis using Cu Ka radiation in the 2θ range from 20° to 60°, with a scanning step of 0.01°. Roughness on the surface of the films was examined by atomic force microscopy (AFM, FM-Nanoview 1000). A picosecond laser pump–probe system was used for real-time reflectivity measurement. The light source used for irradiating the samples was a frequency-doubled model-locked neodymium yttrium aluminum garnet laser operating at 532 nm wave-length with a pulse duration of 30 ps. Samples with a thickness of 50 nm were prepared for X-ray reflectometry (XRR) measurement to estimate the film density change during crystallization. The device properties of PCM cell were measured using a Tektronix AWG5012B arbitrary waveform generator and a Keithley 2602 A parameter analyzer.