There’s so much good stuff going on at the ACS meeting that it’s tough finding time to blog, so here I am catching up on yesterday’s talks. Let’s kick off by talking about a brilliant session on inorganic nanochemistry. Zhong Lin Wang described his work with piezoelectric ZnO nanowires, especially looking at how they can be used to make nanogenerators for powering devices. One of the latest developments is a widget that produces an oscillating current as it flexes, effectively acting as an AC generator – Nature Nanotechnology subscribers can read a paper about this here. Zhong Lin wowed the audience by showing how such devices could be built into a jacket for a hamster; when the hamster went for a run in its wheel, the animal’s movement generated electricity! (Nano Letters subscribers can see this here.)
Equally impressive was Yi Cui’s talk about the use of nanostructured surfaces for making efficient photovoltaic devices. By making solar cells lined with nanocones or nanodomes of silicon, the energy density of the cells reaches 17.5 mA per square centimetre – which according to Yi is “world-beating”. The silicon nanocones are better at trapping light than films of amorphous silicon, absorb light across a range of wavelengths (Yi showed data spanning 400 to 800 nanometres), and also efficiently absorb light that strikes the cell obliquely. I was particularly struck by pictures that compared amorphous silicon with the nanostructured stuff – amorphous silicon is grey, whereas the nanocone material is totally black, thus providing a simple demonstration of light absorption properties that even I could understand!
There was lots of other cool stuff (including a tantalizing mention from Yi about nanoribbon topological insulators that should solve a fundamental problem in spintronics, manuscript currently in press), but now I really want to say something about polymers (see my next blog entry)…
Andrew Mitchinson (Senior Editor, Nature)