Dissertation in the field of Radio Engineering, Irina Nefedova

The title of thesis is ”Electrical and optical properties of carbon nanotube and silver nanowire layers for low-THz applications”.

Modern devices operating at low THz frequencies require higher efficiency and high functionality but at the same time lower cost and smaller dimensions of the compo-nents. Novel nanomaterials like carbon nanotubes, graphene and silver nanowires are promising material candidates for the near future of radio engineering. However, high frequency properties of these nanomaterials are not well studied up-to-now. In this thesis, characterization of nanomaterial properties at millimeter wave and optical frequencies are studied both experimentally and theoretically.

The experimental techniques include millimeter wave transmission and reflection measurements of a dielectric rod waveguide (DRW) loaded with a nanomaterial layer in order to find out its dielectric properties and optical measurements of the layer transparency, in order to find the dependence of film resistivity and transparency on lengths of nanowires. The first part of the thesis deals with millimeter wave charac-terization. Attenuation constant, found from the S-parameter measurements, was used as a basic parameter for the developed theoretical model for determination of the complex dielectric constant of nanomaterial layer. Obtained parameters were suc-cessfully used in numerical simulations in assigning material properties. The second part of the thesis relates to fabrication and optical measurements of transparent con-ductive layers based on silver nanowires. The aging of the fabricated layers were studied as well.

Opponent: Professor Hartmut Roskos, Johann Wolfgang Goethe Universität, Germany

Supervisor: Professor Antti Räisänen, Aalto University School of Electrical Engineering, Department of Electronics and Nanoengineering

Dissertation website

Contact information
Irina Nefedova
+358 50 3693 004
Irina.nefedova@aalto.fi