Introduction of Graphene

1
Introduction of Graphene
2
What is graphene?

• The common graphite is formed by stacking a layer
  of planar carbon atoms arranged in a honeycomb
  order. The interlayer force of graphite is weak,
  and it is easy to peel off to form a thin
  graphite sheet. When the graphite sheet is peeled
  off into a single layer, such a single layer
  having a thickness of only one carbon atom is
  graphene.

3
The first graphene

• The first graphene material was developed in 2004
  by Professor Andrei Heim and his assistant,
  Konstantin Novoselov. They separated the graphite
  into smaller pieces, peeled off the thinner
  graphite sheets from the pieces, and then taped
  the sides of the sheets with plastic tape and
  torn the tape. By repeated pasting and tearing, a
  thinner and thinner graphite sheet is obtained
  until it finally becomes a monoatomic layer of
  graphene.

4
The structure of graphene

• Graphene is carbon material composed of carbon
  atoms arranged in a hexagonal lattice neatly, and
  its structure is very stable. The connection
  between the carbon atoms of graphene is very
  flexible, and when an external mechanical force
  is applied, the carbon atom plane is bent and
  deformed. In this way, the carbon atoms do not
  need to be rearranged to accommodate the external
  force, which ensures the stability of the
  graphene structure, and makes the graphene harder
  than the diamond, and can also be stretched like
  a rubber. This stable lattice structure also
  gives graphene excellent electrical conductivity.
  When electrons in graphene move in orbit, they do
  not scatter due to lattice defects or
  introduction of foreign atoms.

5
Characteristics of graphene

• Graphene has proven to be the thinnest and
  hardest substance ever found in the world. Its
  thickness is only 0.335 nanometers, even if
  200,000 films are stacked together, it is only as
  thick as one hair. The single-layer graphene is
  almost transparent, and its molecular arrangement
  is tight, and even the smallest atomic size of
  the crucible cannot pass. Another characteristic
  of graphene is that its conductive electrons can
  move unobstructed in the crystal lattice and the
  speed is extremely fast, far exceeding the moving
  speed of electrons move in metal conductors or
  semiconductors. And the thermal conductivity of
  graphene exceeds all known materials. The above
  characteristics of graphene are very advantageous
  for the development of ultra-thin flexible OLED
  displays. It is said that Samsung's researchers
  have produced transparent and flexible displays
  made of materials such as multilayer graphene.

6
The applications of graphene

• In recent years, a series of advances have been
  made in the research of new electronic materials
  represented by graphene. Studies have shown that
  graphene films have field emission
  characteristics comparable to those of carbon
  nanotube films, so they have a very broad
  application prospect in semiconductor devices and
  flat panel displays. Due to the unique
  two-dimensional structure and excellent
  crystallographic quality of graphene, it provides
  an ideal platform for the study of quantum
  electrodynamic phenomena and has important
  theoretical research value. In addition, graphene
  composited with plastic can be a conductor, and
  its mechanical properties and heat resistance are
  improved. The new material made of graphene and
  plastic is lightweight and sturdy, and it can be
  applied to a new generation of satellites,
  aircraft and automobiles. Besides, graphene can
  be used in high-sensitivity sensors and
  high-performance energy storage devices. In
  recent years, many scientific and
  technical workers in various countries have made
  many new advances in the research on the material
  properties of graphene and the batch preparation
  of graphene devices and materials.