Jan Smotlakha
Joint Institute for Nuclear Research, Russia
Title: Effect of the grain boundaries on the electronic and mechanical structure of graphene
Biography
Biography: Jan Smotlakha
Abstract
The grain boundaries in the graphene nanostructures usually consist of a combination of pentagonal and heptagonal defects. Being not very thick, they create regions of size tenths of nanometers. They arise during the production process and are intimately connected with the internal structure of the corresponding materials. The production process is mostly initiated by the chemical vapor deposition. Of course, the grain boundaries have a huge, usually undesirable influence on the electronic structure of the materials. Depending on the external conditions during the production, there can be qualitative differences in their properties. The resulting structures contain grains of different sizes, distributions and lattice orientations. Numerical calculations for a few samples were performed where the average sizes of the grains fluctuated from 13 to 25nm. They showed a considerable difference in the conductivities and charge carrier mobilities. The mobilities depend on the size of the grain boundaries linearly. Next, different configurations of the defects in the grain boundaries were considered and the corresponding polycrystalline structures showed significant differences in the investigated characteristics.