26. 7. 2013. Seminar: Irena Knežević


Friday 26 July 2013 at 2PM
IPB Library
Seminar organized by Scientific Computing Laboratory

Irena Knežević
Electrical and Computer Engineering University of Wisconsin – Madison, USA

Graphene Plays Dirty: How Impurites and Imperfections Affect the Physics of Graphene Nanostructures

Graphene, a single sheet of graphite, is a material with a two-dimensional honeycomb lattice. Today, it is possible to grow and transfer large-area graphene sheets, which can be patterned into devices used for electronic, photonic, and thermoelectric applications. While pristine suspended graphene has remarkably high electronic and lattice conductivities, the influence of substrate impurities and various atomic-sized imperfections drastically affects the transport of charge and heat in realistic graphene nanostructures. However, the physics of “dirty” graphene is rich and exciting in its own right. In this talk, I will present our recent work on detailed microscopic simulation of (1) ac and dc electronic transport in supported graphene, with emphasis on short-range Coulomb interactions and impurity clustering, and (2) thermal transport in graphene sheets and ribbons, with focus on the diffusive-to-ballistic crossover, the influence of substrate and edge roughness, and grain boundary scattering.

1.M.-H. Bae, Z. Li, Z. Aksamija, P. N. Martin, F. Xiong, Z.-Y. Ong, I. Knezevic, and E. Pop, “Ballistic to diffusive crossover of heat flow in graphene ribbons,” Nature Communications 4, 1734 (2013).
2.Z. Aksamija and I. Knezevic, "Thermal transport in graphene nanoribbons supported on SiO2," Phys. Rev. B 86, 165426 (2012).
3.Z. Aksamija and I. Knezevic, “Lattice thermal conductivity of graphene nanoribbons: anisotropy and edge roughness scattering,” Appl. Phys. Lett. 98, 141919 (2011).
4.N. Sule and I. Knezevic, " Phonon-limited electron mobility in graphene using electronic tight-binding Bloch waves," J. Appl. Phys. 112 , 053702 (2012).

Irena Knezevic in an Associate Professor in the Electrical and Computer Engineering Department of the University of Wisconsin – Madison. Her research activities focus on the simulation of quantum and semiclassical carrier transport in electronic and optoelectronic semiconductor devices, heat transport at the nanoscale and nanostructured thermoelectrics, materials properties at THz frequencies, and developing efficient computational techniques for coupling the dynamics of electrons, phonons, and photons at the nanoscale. Dr. Knezevic is a recipient of the 2005 Palais’ Oustanding Doctoral Student Award, the 2006 NSF Early Career Development (NSF CAREER) award, the 2009 AFOSR Young Investigator Research Program (YIP) Award, as well as the 2011 James G. Woodburn Award for Excellence in Undergraduate Teaching. She is an associate editor of the Journal of Computational Electronics.