Optical Switching And Related Structural Properties Of Epitaxial Ge2sb2te5 Films

We investigate the optical switching process and the related structural properties of (GeTe)(Sb2Te3) epitaxial films close to Ge2Sb2Te5 composition on GaSb(001). While the amorphization process can take place in a single or in multiple steps, the re-crystallization process always takes place in multiple steps. Intermediate stages of the re-crystallization process are characterized by small crystalline islands within the amorphous area. The structural properties are investigated by optical microscopy and electron backscatter diffraction (EBSD) in a scanning electron microscope. The analysis of the EBSD pattern demonstrates that the crystalline islands at intermediate stages of the re-crystallization process exhibit different orientations. We conclude that the re-crystallization process is driven by nucleation without any orientation information from the substrate. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4728221]