Rate Equation Model For The Time Dependence Of The Reflectance Of A Ge2te2sb5 Film During Optical Switching Processes

We apply a rate equation model in order to simulate the measured change of the reflectance of an epitaxially grown Ge2Te2Sb5 (GST) film during optically induced switching between the amorphous and crystalline phases of the material. The amorphization and the re-crystallization process are considered to exhibit different switching rates, which depend on the actual value of the energy fluence of the applied laser pulse. The measured time dependence of the reflectance of the GST film as a measure of its degree of crystallinity is qualitatively reproduced by the rate equation model demonstrating that both processes can occur simultaneously during the switching process, but with different rates. (C) 2013 AIP Publishing LLC.