Dissertation in the field Micro- and nanotechnology, Wonjae Kim

The title of thesis Fabrication and characterization of graphene-based electronic devices

Graphene, a 2-dimensional hexagonal carbon lattice, is a promising material for future electronics. High carrier mobility is viable through the 2D plane and the true atomic thick layer enables to be transparency and flexiblility. A sp2-hybridized bonding in a lattice leads graphene to have physical strength that is about 100 times higher than steel. The property is unique and never found before in other materials. In this thesis, several different sources of graphene are introduced and investigated towards device applications. For fast and cost-effective synthesis of graphene, photo-thermal CVD was developed. The quality of graphene prelimi-narily determined by SEM and Raman is presented. Employing the CVD gra-phene, electronic devices fabricated for a highly tunable-switchable rectifier and an inverter were demonstrated. The devices were realized utilizing three-terminal junction structure. By applying the same graphene layer to the gate electrode, transparent functionality through the device structure was additionally achieved. Finally, a cascaded two TBJ device structure where the output of the first TBJ was utilized as a gate input for the second TBJ was demonstrated. This is a significant step to realize the possibility of layer-by-layer device architecture for graphene-based monolithic integrated circuit.

Opponent: Professor Max Lemme, University of Siegen, Germany, Group of Graphene-based Nanotechnology

Supervisor: Professor Harri Lipsanen Aalto University School of Electrical Engineering, Department of Micro- and Nanosciences

Contact information:
Wonjae Kim
tel. +358 44 3170988
wonjae.kim@aalto.fi