Worksheets2024 Nanotech L4
Total questions: 7
Worksheet time: 35mins
Name
Class
Date
1.
Why was the discovery of graphene surprising?
a)
Due to Merlin-Werner theory.
b)
Since 2D crystals should not be stable at finite temperature.
c)
Since the strong sp2 bonds does not allow remove one layer
d)
Since it was difficult to see it.
2.
Graphene can be created
a)
by exfoliation, which is a slow process resulting in nm-scale flakes.
b)
by CVD, which is good for mass production.
c)
by liquid phase exfoliation, which produces the largest crystals.
d)
only in lab conditions, no way for mass production.
3.
Graphene is ideal for composites, since
a)
van der Waals interaction creates strong bonds.
b)
it can be streached up to 10% inelastically.
c)
it is light and strong.
d)
it can be mixed with plastics.
4.
Graphene is promising for optical applications, since
a)
it is completely transparent for visible light.
b)
it conducts and allows 97% of visible light through.
c)
it has small band gap, good for THz detection.
d)
it has indirect band gap.
5.
Transparent conductors is a potential application of graphene,
a)
since it allows a highly transparent, stretchable, flexible layer.
b)
however it is less transparent than existing ITO layers.
c)
however its sheet resistance is larger than for ITO.
d)
however its toxicity is a problem.
6.
Graphene band structure is special
a)
since it has inverted gap.
b)
since it has a linear spectrum with zero band gap.
c)
since it has 2D Brillouin zone.
d)
since it has large mobility.
7.
In Van der Waals heterostrucutres
a)
single layer 2D crystals are grown on top of each other by MBE.
b)
the angle of the different layers matters in electron structure.
c)
dust between layers does no allow clean interfaces.
d)
van der Waals interaction electron hopping from layer to layer.
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