Tailoring phase change materials for nanophotonic applications

Abstract

Controlling a state of material between its crystalline and glassy phase has fostered many real-world applications. Switching between these states is particularly interesting if accompanied by a significant change of optical properties. Phase change materials provide the combination of fast switching and a pronounced property change. For nanophotonic applications it is crucial to tailor the crystallization kinetics, the length of the switching processes and as the optical contrast. We devise design rules for crystallization and vitrification kinetics and the contrast of optical properties. We discover a clear stoichiometry dependence along a line connecting regions characterized by two fundamental bonding types, metallic and covalent bonding. Increasing covalency slows down crystallization siginficantly and promotes vitrification. A quantum-chemical map explains these trends and provides a blueprint to design crystallization kinetics, nanostructure control and property contrast.

Authors 1

1. Matthias Wuttig corresponding Aachen

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen Univ. (Germany)