Colloidal Quantum Dots Make Spray-On Solar Cells Possible
Illan Kramer and colleagues have just created a new way to spray solar cells onto flexible surfaces. They are using miniscule light-sensitive materials known as colloidal quantum dots (CQDs).
(Spray-on solar cell video)
"My dream is that one day you'll have two technicians with Ghostbusters backpacks come to your house and spray your roof," said Kramer, a post-doctoral fellow with The Edward S. Rogers Sr. Department of Electrical & Computer Engineering at the University of Toronto and IBM Canada's Research and Development Centre.
Solar-sensitive CQDs printed onto a flexible film could be used to coat all kinds of weirdly shaped surfaces, from patio furniture to an airplane's wing. A surface the size of your car's roof wrapped with CQD-coated film would produce enough energy to power three 100-Watt light bulbs -- or 24 compact fluorescents.
He calls his system sprayLD, a play on the manufacturing process called ALD, short for atomic layer deposition, in which materials are laid down on a surface one atom-thickness at a time.
Kramer built his sprayLD device using parts that are readily available and rather affordable -- he sourced a spray nozzle used in steel mills to cool steel with a fine mist of water, and a few regular air brushes from an art store.
"This is something you can build in a Junkyard Wars fashion, which is basically how we did it," said Kramer. "We think of this as a no-compromise solution for shifting from batch processing to roll-to-roll."
I read about this idea twenty years ago; sf writer Larry Niven popularized it in his 1995 story The Woman in Del Rey Crater:
Black Power, they call it. It turns sunlight into electricity, just like any solar power converter, but you spray it on.
(Read more about Niven's black power)
Seabreacher, H.G. Winter's 1939 Torpoon
'Ken lay full-length in the padded body compartment, his feet resting on the controlling bars of the directional planes, hands on the torpoon's engine levers.' - HG Winters, 1939.