Imagine a power station that’s literally sprayed onto your roof —and could match the colour of your tiles.

Thin film solar cells are thinner, cheaper and more versatile than the traditional silicon solar panels. Spray-on solar is a next step in the evolution of on-site power generation.

“These cells can be made with semiconductor dye materials, so you can match them to any colour or pattern you like—they’ll just convert that part of the solar spectrum into electricity. In the future we could have billboards that act as solar panels,” says Dr Gerry Wilson of CSIRO’s flexible electronics team.

Organic photovoltaic (OPV) cells are made from organic (carbon-containing) materials instead of silicon, making them lighter and less expensive than conventional silicon solar panels.

Gerry is part of the Victorian Organic Solar cell Consortium (VICOSC). The group has already seen great success developing printable thin film solar, which helps make more affordable lighting and power available to developing countries. Spray- on solar takes this to a new level. Gerry says the key difference between printable and spray-on solar films is the way they’re manufactured.

“To print OPVs, you have to make concentrated solutions to produce a strongly absorbing but thin film. Unfortunately, many of these materials are sparingly soluble, so we use [toxic] organic solvents, like dichlorobenzene,” Gerry says, “With spray on-solar you don’t need concentrated solutions—you just spray longer with a normal solvent.

“This opens up the use of a broader range of less soluble materials and it cuts the use of the harmful solvents. Plus, the spraying process allows you to build in a charge gradient—to make a more efficient cell.”

Photo: A spray head used to make spray-on solar cells at CSIRO
Credit: Doojin Vak
GERRY WILSON IS DEVELOPING SPRAY-ON SOLAR CELLS.
CREDIT: ISTOCKPHOTO

CSIRO Materials Science and Engineering, Gerry Wilson, +61 3 9545 2205
gerry.wilson@csiro.au, www.csiro.au/flexibleelectronics/