Category Chemistry/Nanotechnology

Depiction of photon recycling inside the crystalline structure of perovskite. Credit: Criss Hohmann

Scientists have discovered that a highly promising group of materials known as hybrid lead halide perovskites can recycle light which could lead to large gains in the efficiency of solar cells. As well as being cheap and easy to produce, perovskite solar cells have, in the space of a few years, become almost as energy-efficient as silicon – the material currently used in most household solar panels.

By showing that they can also be optimised to recycle light, the new study suggests that this could just be the beginning...

Illustration of a graphene nanoribbon with zigzag edges and the precursor molecules used in its manufacture. Electrons on the two zigzag edges display opposite directions of rotation (spin) — “spin-up” on the bottom edge (red) or “spin-down” on the top edge (blue). Credit: EMPA

Scientists have now managed to synthesise GNR with perfectly zigzagged edges using suitable carbon precursor molecules and a perfected manufacturing process. The zigzags followed a very specific geometry along the longitudinal axis of the ribbons. This is an important step, because researchers can thus give graphene ribbons different properties via the geometry of the ribbons and especially via the structure of their edges.

With molecules in a U-shape, which they allowed to grow together to form a snake-like shape, ...

ORNL’s tough new plastic is made with 50 percent renewable content from biomass. Credit: Oak Ridge National Laboratory, U.S. Dept. of Energy; conceptual art by Mark Robbins (hi-res image)

Your car’s bumper is probably made of a moldable thermoplastic polymer called ABS, shorthand for its acrylonitrile, butadiene and styrene components. Light, strong and tough, it is also the stuff of ventilation pipes, protective headgear, kitchen appliances, Lego bricks and many other consumer products. Useful as it is, one of its drawbacks is that it is made using chemicals derived from petroleum.

Now, Dept of Energy’s Oak Ridge National Lab researchers have made a better thermoplastic by replacing styrene with lignin, a brittle, rigid polymer that, with cellulose, forms the woody cell walls of plants...