superlattice tagged posts

Hydrogen fuel is a promising alternative to fossil fuels that only emits water vapor when used and could thus help to lower greenhouse gas emissions on Earth. In the future, it could potentially be used to fuel heavy-duty transport vehicles, such as trucks, trains, and ships, as well as industrial heating and decentralized power generation systems.

Unfortunately, most current methods to produce hydrogen rely on the burning of fossil fuels, which limits its environmental advantages. Given its potential, many energy engineers worldwide have been trying to devise more sustainable strategies to produce hydrogen on a large scale.

One proposed method for the clean production of hydrogen is known as...

Researchers from the RIKEN Center for Emergent Matter Science and collaborators have succeeded in creating a “superlattice” of semiconductor quantum dots that can behave like a metal, potentially imparting exciting new properties to this popular class of materials.

Semiconducting colloidal quantum dots have garnered tremendous research interest due to their special optical properties, which arise from the quantum confinement effect...

Finding paves the way for new generation of opto-electronic applications. Quantum dots are clusters of some 1,000 atoms which act as one large ‘super-atom’. It is possible to accurately design the electronic properties of these dots just by changing their size...

Image of one of the graphene-based devices Xu and colleagues worked with. Credit: Lei Wang

In traditional light-harvesting methods, energy from 1 photon only excites 1 electron or none depending on the absorber’s energy gap. The remaining energy is lost as heat. But a new article describe an approach to coax photons into stimulating multiple electrons. Their method exploits some surprising quantum-level interactions to give one photon multiple potential electron partners.

Wu and Xu in UW’s Dept of Materials Science & Engineering and the Det of Physics, made this surprising discovery using graphene.
The researchers took a single atom layer of graphene and sandwiched it between 2 thin layers of boron-nitride. Electrons do not flow easily within boron-nitride so it is an insulator.

When the g...