Spray Solar Cells on Any Surface http://www.eet
Post# of 22453
http://www.eetimes.com/document.asp?doc_id=1324944
PORTLAND, Ore. -- Spray-on solar cells have been a dream for a decade, but now the IBM Canada's Research and Development Centre -- a consortium of seven universities including the University of Toronto where this work was done -- may have found the key to make spray-on solar cells a reality.
The secret ingredient, according to Illlan Kramer, an IBM employee who works as a post-doctoral fellow in professor Ted Sargent's group at the University of Toronto, is collodial quantum dots.
"Colloidal Quantum Dots are semiconductor nanoparticles that are suspended in the solution phase. Because the nanoparticles are so small, they cannot be seen by eye, but they do make the solution look black, much like an ink. When you have materials like this, you can allow your imagination to run wild with respect to how you want to deposit them into a film -- ink-jet printing, slot-dye coating, or through a spraying method. We played with both the ink solution and the spray droplet size to arrive at a scenario where the colloidal quantum dots were 'almost dry' by the time the spray reached the substrate," Kramer told EE Times.
Quantum dots are increasingly being used for brighter light-emitting-diodes (LEDs) as well as novel solar cells built into windows. Now the IBM Canada's Research and Development Centre and the University of Toronto believe they are on the road to spray-on solar cells using quantum dots in this century. Kramer calls the devices sprayLD, a play on ALD -- atomic layer deposition.