Wall-to-wall power

Solar cells printed like wallpaper.

Philip Ball

On a roll: solar panels could soon be as cheap and easy to print as wallpaper.© Photodisc / NSU

Solar cells might one day be produced by the roll, as cheaply and easily as wallpaper. Scientists in Arizona are using screen-printing, a technique developed for patterning fabrics, to produce plastic solar cells¹.

The technique is another step towards the general availability of solar power from flexible devices on plastic sheets or glass panels. The basic materials of a photovoltaic cell are inexpensive, but combining them into a working device is currently costly. This limits our exploitation of the sun's potential to provide clean energy.

The organic cells manufactured by Ghassan Jabbour and colleagues at the University of Arizona in Tucson have about a quarter of the efficiency of commercial silicon devices (which turn 10-20 per cent of light energy into electricity). But, being cheap to produce, they can make up in quantity what they lack in quality.

In conventional screen-printing, a taut piece of fabric, patterned by masking some areas with substances such as wax that repel colouring agents, is covered with ink or dye. The screen is then held horizontally over the object to be printed, and a rubber blade is swept across the back, pressing the coloured surface down to produce an image.