Silicene
Encyclopedia
Silicene is a two-dimensional allotrope of silicon
, similar to graphene
.
, they studied self-assembled silicene nanoribbons and silicene sheets deposited onto a silver crystal with atomic resolution. The images revealed hexagons in a honeycomb structure similar to that of graphene
.
Density functional theory
calculations showed that silicon atoms tend to form such honeycomb structures on silver, and adopt a slight curvature that makes the graphene-like configuration more likely.
Recently silicene has been reported to grow on ZrB2
substrate.
In addition to its potential compatibility with existing semiconductor techniques, silicene has the advantage that their edges do not exhibit oxygen reactivity.
Structure of a typical silicene cluster showing ripples across the surface.
Recent DFT calculations have revealed that silicene clusters are excellent materials for FET
applications. Interestingly, 2D silicene is not really planar and there seems to be chair-like puckering distortions in the rings. This leads to ordered ripples on their surface. Hydrogenation of silicenes to silicanes is quite exothermic. This has led to the prediction that the process of conversion of silicene to silicane (hydrogenated silicene) can be a prospective candidate for hydrogen storage. Unlike, graphite which consists of weakly held stacks of graphene layers through dispersion forces, the interlayer coupling in silicenes are very strong.
Other references:
Silicon
Silicon is a chemical element with the symbol Si and atomic number 14. A tetravalent metalloid, it is less reactive than its chemical analog carbon, the nonmetal directly above it in the periodic table, but more reactive than germanium, the metalloid directly below it in the table...
, similar to graphene
Graphene
Graphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, who described single-layer...
.
History
Although theorists have speculated about the existence and possible properties of silicene, it has not been observed. In 2010, researchers have observed for the first time silicon structures that are suggestive of silicene. Using the scanning tunneling microscopeScanning tunneling microscope
A scanning tunneling microscope is an instrument for imaging surfaces at the atomic level. Its development in 1981 earned its inventors, Gerd Binnig and Heinrich Rohrer , the Nobel Prize in Physics in 1986. For an STM, good resolution is considered to be 0.1 nm lateral resolution and...
, they studied self-assembled silicene nanoribbons and silicene sheets deposited onto a silver crystal with atomic resolution. The images revealed hexagons in a honeycomb structure similar to that of graphene
Graphene
Graphene is an allotrope of carbon, whose structure is one-atom-thick planar sheets of sp2-bonded carbon atoms that are densely packed in a honeycomb crystal lattice. The term graphene was coined as a combination of graphite and the suffix -ene by Hanns-Peter Boehm, who described single-layer...
.
Density functional theory
Density functional theory
Density functional theory is a quantum mechanical modelling method used in physics and chemistry to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by...
calculations showed that silicon atoms tend to form such honeycomb structures on silver, and adopt a slight curvature that makes the graphene-like configuration more likely.
Recently silicene has been reported to grow on ZrB2
Zirconium diboride
Zirconium diboride is a highly covalent refractory ceramic material with a hexagonal crystal structure. ZrB2 is an Ultra High Temperature Ceramic with a melting point of 3246 °C...
substrate.
In addition to its potential compatibility with existing semiconductor techniques, silicene has the advantage that their edges do not exhibit oxygen reactivity.
Structure of a typical silicene cluster showing ripples across the surface.
Recent DFT calculations have revealed that silicene clusters are excellent materials for FET
Field-effect transistor
The field-effect transistor is a transistor that relies on an electric field to control the shape and hence the conductivity of a channel of one type of charge carrier in a semiconductor material. FETs are sometimes called unipolar transistors to contrast their single-carrier-type operation with...
applications. Interestingly, 2D silicene is not really planar and there seems to be chair-like puckering distortions in the rings. This leads to ordered ripples on their surface. Hydrogenation of silicenes to silicanes is quite exothermic. This has led to the prediction that the process of conversion of silicene to silicane (hydrogenated silicene) can be a prospective candidate for hydrogen storage. Unlike, graphite which consists of weakly held stacks of graphene layers through dispersion forces, the interlayer coupling in silicenes are very strong.
Other references: