Category Physics

Quantum-confined bandgap narrowing mechanism through which the absorption of two UV absorbers, namely the graphene quantum dots (GQDs) and TiO2 nanoparticles, can be easily extended into the visible light range in a controllable manner. Such a mechanism may be of great importance for light harvesting, photocatalysis and optoelectronics.

For the 1st time resesarchers have found a quantum-confined bandgap narrowing mechanism where UV absorption of the graphene quantum dots and TiO2 nanoparticles can easily be extended into the visible light range. Such a mechanism may allow the design of a new class of composite materials for light harvesting and optoelectronics...

This reproduction of The Starry Night contains 65,536 glowing pixels and is just the width of a dime across. Credit: Paul Rothemund and Ashwin Gopinath/Caltech

A hurdle for large-scale integration of molecular devices on chips has been removed by a technique that allows humanmade DNA shapes to be placed wherever desired, to within a margin of error of just 20nm. Using folded DNA to precisely place glowing molecules within microscopic light resonators, researchers at Caltech have created one of the world’s smallest reproductions of Vincent van Gogh’s The Starry Night...

A thermal probe tests heat conductance in a sample of silicon dioxide nanoparticles. The material could potentially conduct heat at an efficiency higher than that of conventional materials. Credit: Rob Felt, Georgia Tech

Not beach sand, but silicon dioxide nanoparticles coated with a high dielectric constant polymer can inexpensively provide improved cooling for increasingly power-hungry electronic devices. The silicon dioxide doesn’t do the cooling itself. Instead, the unique surface properties of the coated nanoscale material conduct the heat at potentially higher efficiency than existing heat sink materials. The theoretical physics is complicated, involving nanoscale electromagnetic effects created on the surface of the tiny silicon dioxide particles acting together.

The bottom line cou...

This is an atomic force microscopy image of a graphene sheet draped over a Bacillus bacterium (left). The bacterium is about 1 micron or 1/25,000 of an inch wide. After applying vacuum and heat treatment, regular wrinkles form in the graphene (right, at twice the magnification). Credit: UNIVERSITY OF ILLINOIS AT CHICAGO/Vikas Berry

New nanomaterial conducts differently at right angles. Now University of Illinois at Chicago researchers have used rod-shaped bacteria – precisely aligned in an electric field, then vacuum-shrunk under a graphene sheet – to introduce nanoscale ripples in the material, causing it to conduct electrons differently in perpendicular directions...