Researchers at Notre Dame have developed a simple and cheap alternative to traditional solar cells: solar paint. The one-coat paint, made with semiconducting nanoparticles, achieved a one percent conversion rate when tested using artificial sunlight. This is far behind other solar technologies -- which fall in the 10 to 15 percent range, generally -- but the ease of manufacturing and use are clear advantages of the paint idea. They published a paper on the subject in ACS Nano.
The researchers, led by Prashant Kamat, created an alcohol-based paste consisting of cadmium sulfide, cadmium selenide, and titanium oxide semiconducting nanoparticles. They then annealed the paste on a conducting glass surface, and sandwiched an electrolyte solution between the paste and a graphene composite electrode to achieve their one percent efficiency. A quick video explaining the process is below.
Clearly, the Notre Dame group will have to make some improvement in efficiency for this to be a viable alternative to traditional solar cells. "But this paint can be made cheaply and in large quantities," Kamat says in a press release. "If we can improve the efficiency somewhat, we may be able to make a real difference in meeting energy needs in the future." This work joins earlier efforts toward sprayable, printable, and paintable solar tech, so it's good to see progress in the field. There is reason for optimism here, so I suppose we can forgive the Notre Dame team their product's unfortunate pun of a name: Sun-Believable.
(Image and video via Notre Dame)