Solar Cells likes pop music

Engineering researchers at Queen Mary University and the Imperial College of London have created photovoltaic (PV) cells that work better when they hear rock music.

Traditional silicon-based solar cells convert sunlight into electricity efficiently, but they can be awkward to work with and expensive to produce. So Steve Dunn at Queen Mary University in London and James Durrant at Imperial College London have been experimenting with zinc oxide, which is much cheaper and can be made into thin, flexible films. The only drawback is that its efficiency is just 1.2 per cent, a small fraction of what silicon is capable of.

To improve this, Dunn and Durrant took advantage of another of zinc oxide's properties. Nanoscale rods of the material wobble in response to mechanical stress – such as the vibrations produced by sound – and generate an electric field.

The PV cells are made by growing zinc-oxide nanorods. Zinc-oxide is a semiconductor material with piezoelectric characteristics. It’s the latter property that converts sound into electricity. The scientists found that sounds as low as 75 decibels - slightly louder than a vacuum cleaner - can increase the efficiency of the solar cell by up to 45%.

Although any sound at a high enough level can trigger the effect, it was more pronounced in the presence of rock and pop music. The researchers concluded that rock-and-roll’s high frequencies were favored by the solar cells.