Recently, nanocarbon materials has attracted a great interest. Graphene and carbon nanotubes have unique low-dimensional nanoscale structures and have extraordinary high carrier mobility which is higher than that of silicon.
In addition, they are mechanically flexible and transparent. Therefore, the nanocarbons make an attractive and exciting scientific research field and a number of groups in the world are developing various kinds of applications, such as electronic devices, composite materials, and batteries.
In our group, we are studying the following topics mainly focusing on nanocarbon materials.
- Highly controlled synthesis of nanocarbon materials
- Measurement of physical and chemical properties
- Development of new applications
- Investigations into novel functional nanomaterials
Chemical Vapor Deposition Growth of Graphene
Graphene is a two dimensional (2D) atomic sheet consisting of honeycomb lattice of carbon atoms. This extremely thin carbon films shows a very high mobility, optical transparency, and mechanical flexibility, which make graphene promissing material in electronic applications.
In our group, we have developed the chemical vapor deposition growth of high quality graphene films based on our original heteroepitaxial approach. We also study the growth mechanism of graphene on metal catalysts.
New Graphene Nanostructures
The absence of band gap in graphene makes difficult to develop semiconductor devices, although graphene shows the very high carrier mobility. Narrow stripes of graphene, so-called graphene nanoribbons, and double-layer graphene are expeceted to have band gap.
We are studying the new methods of controlled synthesis or fabrications of these new nanostructures of graphene.
Physical Properties and Applications of Graphene
We also study electronic properties of graphene by making devices such as field-effect transistors to develop possiblity of ”carbon electronics”.
For flexible electronics, effects of strain on graphene's propertes are also investigated in our group.
Controlled Synthesis of Carbon Nanotubes and Applications
Carbon nanotube is one-dimensinal carbon cylinder which also have promissing properties. Applications to integrated circuits and transparent electrodes are expected.
For realizing the electronic devices, it is important to assemble carbon nanotubes in a controlled manner.
We discovered a new method to produce horizontally-aligned carbon nanotubes and have developed this unique finding.
New Two-Dimensional Nanosheets
Inorganic nanomaterials are also interesting materials in terms of quantum size effect. We are studying the CVD method to synthesize new two-dimensional nanomaterials. We recently have succeeded in growing the nanosheets of superconducting NbS2 on graphene.