Thanks to Peter Bøggild!
Thanks to Peter Bøggild!
How stable are the water functionalized groups?
Answer - by exfoliating graphene layers, it is possible, due to the defined direction of the layers upon exfoliation. However, it is also a very difficult, and non-reproducable process. It is not possible to do it dynamically as of yet
How do you change the angle between the graphene layers? Can you do that in an experiment today?
Tips to the audience: If you want make low-dimensional materials, try to use materials that are initially low-dimensional
The Hysteresis of the graphene FET is dependent on the amount of water molecules stuck to the surface
Graphene FET's do not have a very stable/good "Off" state, seeing that the "Off" state is a peak in the gate voltage diagram vs resistance diagram, as compared to MOSFET's that have platueaus
He now turns over to Molecular switches
One of the students that Peter has supervised was convinced they could make superlattices of nanostructured graphene. This turned out to work, as they were able to pattern graphene and achieve interesting results
The band structure changes a lot with the rotation angle of the top layer. In fact, it turns out that graphene may be used as superconductors at certain angles!
leading to beautiful band structures!
The band structure of these superlattices then turn out to be fractured
(Moire) Superlattices of Graphene can be formed by having 2 or more layers, not directly stacked onto each other, but where the top layer is twisted by a certain degree
Van der Waals (CdW) forces are essential when handling 2D materials. Peter and his group has showed that junctions may be formed by simply sticking 2D layers together by VdW forces. These forces also help to expel impurities (e.g. water) from the structures.
The general method for growing layers is to let a material, such as Md, to diffuse through a gold film, and let it react with another element at the gold surface. This yields one-layered crystals
Peter Bøggild became a professor at the Technical university of Denmark 4 years ago
The amount of possible combination, both chemically and structurally, result in endless opportunities for these materials
The edges may then be regarded as one-dimensional structures
The 2-dimensional materials can be stacked in groups which yields new properties to the structure
He now tries to convince us that quasiparticles are not as difficult as it may sound
His presentation is about 2-dimensional materials, and he starts off with the most famous one: Graphene
Welcome to a new day of INASCON!
We are ready to start the day, and welcome Peter Bøggild and his "magic" nobs!