Upgrade for thin solar cell efficiency

Researchers have developed a nanostructured covering that can boost efficiency

Colour capacity: A wider range of wavelengths are absorbed

Researchers at the University of York have developed a covering that can boost the efficiency of thin solar cells. The nanostructured surface is similar to a grating that directs sunlight into silicon film photo-voltaics.

Thin-film solar cells are just a few microns thick, and experts believe they represent the next generation for solar power. Thin panels use less material and are cheaper to produce than the thicker, 0.5mm panels that can be seen on roofs around the country. But until now, thin films have not been able to absorb all the wavelengths of sunlight as thicker panels can.

The new covering is composed of quasi-random nanostructures which optimise the range of wavelengths that can pass into the cells. Professor Thomas Krauss, head of the photonics group in the university’s department of physics, said: “It’s an ingenious design that allows you to control the defraction exactly as you need it for a solar cell. Sunlight is many colours, so you need to make sure all the colours are directed into
the thin film.” 

Krauss believes that the development will allow thin-film cells to compete with thicker cells in terms of efficiency.

He is working on a research project with the 3sun consortium to work out how the coverings can be integrated into solar film manufacturing. The group includes Italian electronics firm STMicroelectronics, Italian power provider Enel and Japanese technology company Sharp.

One of the challenges, he said, will be upscaling the technology, which is currently at centimetre scale, to match solar panels that are on the metre scale.

Krauss worked with scientists at the University of St Andrews and Sun Yat-sen University in China.