semiconductor tagged posts

Gif of the device in action. Probes inject positive and negative charges in the light emitting device, which is transparent under the campanile outline, producing bright light. Credit: Javey lab

UC Berkeley engineers have built a bright-light emitting device that is millimeters wide and fully transparent when turned off. The light emitting material in this device is a monolayer semiconductor, just 3 atoms thick. The device opens the door to invisible displays on walls and windows – displays that would be bright when turned on but see-through when turned off – or in futuristic applications such as light-emitting tattoos, according to the researchers...

The microscopic ribbons lie criss-crossed on the gold substrate. Credit: EMPA

Transistors based on carbon nanostructures: what sounds like a futuristic dream could be reality in just a few years’ time. Scientists have now produced nanotransistors from graphene ribbons that are only a few atoms wide. Graphene ribbons have special electrical properties that make them promising candidates for the nanoelectronics of the future: While graphene is a conductive material, it can become a semiconductor in the form of nanoribbons. This means that it has a sufficiently large energy or band gap in which no electron states can exist: it can be turned on and off – and thus may become a key component of nanotransistors.

The smallest details in the atomic structure of these graphene bands, however, have m...

Various configurations of oxygen adsorption with corresponding energies. (a) Sulphur, molybdenum, and oxygen are represented by yellow, blue, and red spheres, respectively. The sulphur vacancy site is represented by the cross. (b) Nudged elastic band calculation of the energy barrier for migration of an oxygen molecule towards a sulphur vacancy and respective trapping. The energy barrier, measured from the starting point, is 56 meV. The calculation was performed in the spin-averaged state. (c) Calculated ionization levels for relevant defects (all energies are in eV). VBM and CBM refer to the valence band maximum and conduction band minima, respectively. (d) Representation of the charge density of the trapped electrons at sulfur vacancies.

National University of Singapore (NUS) researchers...

Berkeley Lab researchers have experimentally confirmed strong in-plane anisotropy in thermal conductivity along the zigzag (ZZ) and armchair (AC) directions of single-crystal black phosphorous nanoribbons. Credit: Junqiao Wu, Berkeley Lab

Researchers have confirmed single-crystal black phosphorous nanoribbons display a strong in-plane anisotropy in thermal conductivity, up to a factor of 2, along the zigzag and armchair directions of single-crystal black phosphorus nanoribbons. An experimental revelation that should facilitate the future application of this highly promising material to electronic, optoelectronic and thermoelectric devices.

“Imagine the lattice of black phosphorus as a 2D network of balls connected with springs, in which the network is softer along one direction of the plan...