3D dye-sensitised solar cell developed

Dan Rogers - 23 Nov 2009

Solar energy harvesting could be added to many new areas, following the development of 3D dye-sensitised solar cells (DSSCs).

Researchers at the Georgia Institute of Technology have created a nanofibre DSSC structure that can be applied to a wide variety of materials and can generate energy remotely.

While the 3D DSSC is currently not competitive in terms of efficiency, the ability to place solar nanomaterials on surfaces without affecting shape and barely adding weight creates a number of opportunities, such as appearing on the surfaces of car bodywork or the walls of buildings.

Lead researcher Zhong Lin Wang explains: 'If you put a silicon solar cell, for instance, on a car, it wouldn't look terrific and you would have to consider how it would affect resistance.

'Our solar cell technology could be put on the surface of a car and it would be invisible, but still generate energy.'

Integration

The 3D DSSCs consist of zinc oxide nanowires, which enhance the surface area for light absorption. Optical fibres in the top half of the cell structure repeatedly reflect light down the DSSC, so that there are more opportunities to absorb light.

By not affecting the shape or structure of an object and being applicable to many materials, Wang believes that the 3D DSSC technology could be used in places where current solar technology is not suitable because of weight, aesthetics or host surface materials.

Wang adds: 'We've had a few calls already from people that are interested, for instance from US-based aerospace engineering companies. This DSSC could be integrated onto the surface of an aeroplane.

'Where silicon is very brittle and couldn't take the forces exerted on an aeroplane's surface - and a silicon cell would change the aerodynamics of the plane - these optical fibres could be embedded in the material of the structure.'

Remote sensing

Aerospace companies are keen to find ways in which to power the multitude of electronics present on their planes, particularly as conventional circuitry is an issue when applied in operating conditions.

Wang says: 'Aeroplanes use many sensors to monitor pressure and these DSSCs could be used to power wireless sensors, as wires are a liability problem.

'Powering thousands of sensors with solar energy would save much engineering work.'

The research, funded by the US National Science Foundation, the Defense Advanced Research Projects Agency and the KAUST Global Research Partnership, is now working on scaling up lab production of the nanowires for the 3D DSSCs and looking to double the efficiency of the cells.

Wang comments: 'If we can get up to 6-7% efficiency then this technology will become immediately applicable.'