Dynamics of reversible optical properties switching of Ge2Sb2Te5 thin films at laser-induced phase transitions

• Reversable laser-induced phase transition of Ge 2 Sb 2 Te 5 thin film functional coating and related on this transition’s changes in optical properties. • High optical properties contrast for two stable reversible laser-induced phase states. • Transmissivity and reflectivity changing during thin film laser-induced phase changing process time-resolved study. • Thin film temperature kinetics’ computational model. Paper presents the study of Ge 2 Sb 2 Te 5 (GST) thin films phase transitions’ dynamics determined by the rate of their optical coefficients change. The phase transitions were initialized by laser pulses with 15 ns duration at a wavelength of 532 nm and confirmed by X-ray diffraction analysis. Energy fluence was 22 mJ/cm 2 for film crystallization and 54 mJ/cm 2 for reamorphization. The time for a complete change of GST film reflectivity associated with the crystallization process was 23 ns, while the time for a transmissivity change was 32 ns. Taking into account that the reflection is determined to a greater extent by the surface, and the transmission is exclusively by the film thickness, the estimated crystallization rate was ∼3.125 m/s. The time for a complete change in the reflectivity during the film reamorphization 62 ns, and the transmissivity changed in 65 ns. The estimated reamorphization rate was ∼1.538 m/s.