Now, when light strikes the surface
of the superlattice, the interfaces are such that they drive the excited electrons to the hematite and the holes to the chromium oxide.
The ability
of these superlattice stacks to separate electrons and holes was first predicted in 2000 by Kaspar's colleague Dr. Scott Chambers, but no practical applications were envisioned at the time.
For example, while one layer of this new kind
of superlattice can allow a fast flow of electrons through it, the other type of layer can act as an insulator.
This new class
of superlattice structures has tailorable electronic properties for potential technological applications and further scientific studies.»
Metamaterials are artificial nanofabricated constructs whose optical properties arise from the physical structure
of their superlattices rather than their chemical composition.
This new class
of superlattices alternates 2D atomic crystal sheets that are interspaced with molecules of varying shapes and sizes.
Following that success, the team inserted different types of ammonium molecules with various sizes and symmetries into a series of 2D materials to create a broad class
of superlattices.
In superlattice structures, ballistic phonon transport across the whole thickness
of the superlattices implies phase coherence.
Not exact matches
Controlling the self - assembly
of nanoparticles into
superlattices is an important approach to build functional materials.
Taking child's play with building blocks to a whole new level - the nanometer scale - scientists at the U.S. Department
of Energy's (DOE) Brookhaven National Laboratory have constructed 3D «
superlattice» multicomponent nanoparticle arrays where the arrangement
of particles is driven by the shape
of the tiny building blocks.
«The aggregates are arranged in orderly
superlattice structures, which is in stark contrast to the prevailing view that the adsorption
of gas molecules by MOFs occurs stochastically.»
A beam
of light shined through the
superlattice of this zero - index metamaterial was unaffected, as if it had passed through a vacuum.
Northwestern University researchers have developed a new method to precisely arrange nanoparticles
of different sizes and shapes in two and three dimensions, resulting in optically active
superlattices.
The researchers used a combination
of numerical simulations and optical spectroscopy techniques to identify particular nanoparticle
superlattices that absorb specific wavelengths
of visible light.
An artist's concept
of two kinds
of monolayer atomic crystal molecular
superlattices.
Most importantly, the new method easily yields
superlattices with tens, hundreds or even thousands
of alternating layers, which is not yet possible with other approaches.
Such
superlattices can form the basis for improved and new classes
of electronic and optoelectronic devices.
A research team led by UCLA scientists and engineers has developed a method to make new kinds
of artificial «
superlattices» — materials composed
of alternating layers
of ultra-thin «two - dimensional» sheets, which are only one or a few atoms thick.
«A new class
of two - dimensional materials: New kinds
of «
superlattices» could lead to improvements in electronics, from transistors to LEDs.»
The images below the schematic are (left to right): a reconstructed cryo - EM density map
of the tetrahedron, a caged particle shown in a negative - staining TEM image, and a diamond
superlattice shown at high magnification with cryo - STEM.
As Liu explained, «Building diamond
superlattices from nano - and micro-scale particles by means
of self - assembly has proven remarkably difficult.
UCLA researchers develop a new class
of two - dimensional materials: New kinds
of «
superlattices» could lead to improvements in electronics, from transistors to LEDs March 11th, 2018
When mixed and annealed, the tetrahedral arrays formed
superlattices with long - range order where the positions
of the gold nanoparticles mimics the arrangement
of carbon atoms in a lattice
of diamond, but at a scale about 100 times larger.
The same issue
of Science features another approach to engineering
superlattices using DNA nanotechnology: «Diamond family
of nanoparticle
superlattices» [abstract].
An article based on the research, «Oscillatory Noncollinear Magnetism Induced by Interfacial Charge Transfer in
Superlattices Composed
of Metallic Oxides,» appeared in Physical Review X in November.
Creating a
superlattice by placing graphene on boron nitride may allow control
of electron motion in graphene and make graphene electronics practical.
Photoelectrochemical properties
of model corundum and perovskite
superlattices and pn junctions
A research team led by UCLA scientists and engineers has developed a method to make new kinds
of artificial «
superlattices» — materials comprised
of alternating layers
of ultra-thin «two - dimensional» sheets, which are only one or a few atoms thick.
Superlattices are currently built by manually stacking the ultrathin layers on top
of each other.
The new method could also yield
superlattices with thousands
of alternating layers, which is not possible using traditional approaches.
This is an artist's concept
of two kinds
of monolayer atomic crystal molecular
superlattices.