By Brian Bell

AN INTERNATIONAL team of scientists and industrialists at the University of Leicester in the United Kingdom are developing a revolutionary new technique for harnessing green energy.

The Norwegian company EnSol AS has patented a ground-breaking, thin-film solar cell technology and is now working with experts in the university's Department of Physics & Astronomy to develop the novel solar-cell material that could be coated as a thin film on, for example, windows in buildings to produce power on a large scale.

Chris Binns, who is professor of nanotechnology at Leicester, said the collaboration offered a tremendous opportunity to develop a new method for harnessing solar energy.

He continued: "The material has been designed by EnSol AS and is based on nanoparticles that can be synthesised in Leicester. In fact, following some initial investment by the company, the equipment here at the university is uniquely suited in the world to produce small amounts of the material for prototypes.

"The work is important since the solar cells are based on a new operating principle and different to Si solar cells. One of the key advantages is that it is a transparent thin film that can be coated on to window glass so that windows in buildings can also become power generators," said Professor Binns.

"Obviously, some light has to be absorbed in order to generate power but the windows would just have a slight tinting, although a transmission of only 8-10 per cent is common place for windows in the 'sun belt' areas of the world.

"Conversely, the structural material of the building can also be coated with a higher degree of absorption. This could be side panels of the building itself, or even in the form of clip-together solar roof tiles. Also, since it is a thin film that can be coated on to large areas it could become very much cheaper than conventional devices.

"Photovoltaics are destined to form a key power-generating method as part of a low carbon economy, and the new technology will bring that a stage closer," he added.

The material is composed of metal nanoparticles (diameter 10nm) embedded in a transparent composite matrix.

A spokesperson for EnSol said: "The basic cell concept has been demonstrated, and it will be the objective of this research and development project to systematically refine this photovoltaic cell (PV) technology to achieve a cell efficiency of 20 per cent or greater.

"A thin film deposition system with nanoparticle source will be designed and constructed in collaboration with the University of Leicester for the fabrication of prototype cells based on this design.

"This experimental facility will be designed to produce PV cells with an active area in excess of 16 square cm (40mm by 40 mm) deposited on to standard glass substrates. These prototype cells will subsequently be characterised and tested in collaboration with our academic partners.

"EnSol's next-generation PV cell technology has tremendous potential for industrial scale, low environmental impact, cost-effective production via standard 'spray on' techniques," the spokesperson added.