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Journal of Materials Science and Nanotechnology | Volume: 2

November 22-23, 2018 | Paris, France

Materials Physics and Materials Science

International Conference on

honons manifest themselves in all major processes in

semiconductors: they carry heat, limit electron mobility,

affectopticalresponseandtransmitsound.Rapidminiaturization

of electronic devices to nanoscale range requires new

approaches for the efficient management of their heat and

electrical conductions. Oneof these approaches, referred toas

phonon engineering, is related to the optimization of thermal

and electronic properties of nano-dimensional structures due

to modification of their phonon properties.

In this talk a brief reviewof recent theoretical and experimental

results on the phonon and thermal properties of quasi one- and

two-dimensional semiconductor nanostructures and graphene

will be presented. Different possibilities for phonon engineered

optimization of their electrical and thermal conductionwill be

discussed. It will be theoretically demonstrated that strong

reduction of lattice thermal conductivity can be achieved

in semiconductor segmented nanowires or cross-section

modulated nanowires due to the phonon filtering, i.e. trapping

of the certain phonon modes in nanowire segments. It will

be shown that the unique nature of quasi two-dimensional

phonon transport in graphene, twisted graphene and graphene

nanoribbons translates to unusually strong dependence of the

lattice thermal conductivity on extrinsic parameters: flake size

and shape, edge roughness, defects and strain distribution.

Speaker Biography

Denis L Nika is the chair of the Perlin department of theoretical physics and head of the E

Pokatilov laboratory of physics and engineering of nanostructures at the Moldova State

University. He received his PhD in theoretical and mathematical physics from the same

University in 2006. As a visiting researcher he worked in the University of Antwerp,

Belgium, Institute for Integrative Nano sciences, Germany and in the nano-device

laboratory, University of California, USA. His research interests include various topics in

physics of nanostructures such as phonons and thermal transport at nanoscale; multi-

band theory of the electron, hole, exciton and impurity states. He was twice awarded

the honorary title “The Best Young Scientist of the Republic of Moldova”. He has over

80 technical journal publications, 7 reviews, 4 book chapters. His H-index is 30 and his

papers were cited more than 4400 times (ISI Web of Science, 2018).

Denis L Nika

Moldova State University, Republic of Moldova

Phonon Engineering at Nanoscale