The amount of Ge tunes the atomic structure of amorphous GexTe1−x alloy

The atomic structural characteristics of amorphous Ge–Te thin films were studied using the reverse Monte-Carlo simulations based on the electron diffraction data. The results reveal that the fraction of Ge in GexTe1−x tunes the local structural configurations greatly, as well as the amount and volumes of the voids. It further shows that large amounts of Te atoms that do not bond with Ge in non-stoichiometric GexTe1−x discretely distributed in Ge0.4Te0.6 but clustered in Ge0.3Te0.7. These differences give a good understanding on the dramatic change of the crystallization behaviors of GexTe1−x alloys.