Seminarium Fizyki Ciała Stałego

Two-dimensional (2D) materials have recently become an attractive field of extensive research owing to hosting intriguing quantum phenomena and due to their tunable functional properties. In a search for new ultrathin materials, theoretical modeling often consider their free-standing isolated forms. On the other hand, most experimental approaches require the presence of a substrate as a support for that material, which can significantly modify the original properties. In particular the substrate can affect both the atomic and electronic structure of the growing 2D material. Usually, substrate depresses the properties of a material in the isolated form, but can also induce new exotic phenomena. An example of such system is silicene, the silicon counterpart of graphene, known also as the oldest member of 2D Xenes family. The synthesis of silicene requires the presence of a substrate as a support for that material. Depending on the substrate, various allotropic forms of silicene can be synthesized. In particular, planar silicene, unstable in the isolated form, can be prepared on Au(111) thin films grown on a Si(111) substrate in the process of surface segregation. The planar layer of silicene is a part of a more complex Si-Au heterostructure and exhibits exotic electronic properties. During the talk some characteristics of epitaxial silicene, in particular planar silicene heterostructure, will be presented and discussed. Special attention will be paid to the interaction of the planar silicene with the substrate and its consequences in the electronic structure.