Spray-On Solar Power Could Revolutionize the Way We Harness Energy
Environmentalists have long hoped that we could use solar energy to power everything from our houses to our iPads. Now, electrical engineer Illan Kramer has brought us one step closer to the mass production of solar cells, as he has invented a way to spray solar cells onto flexible surfaces, such as Saran Wrap.
In two recent papers in Advanced Materials and Applied Physics Letters, Kramer, a post-doctoral fellow at the University of Toronto, explained that he has devised a method for spraying colloidal quantum dots (CQD's), microscopic, light-sensitive materials, directly onto surfaces. It has been possible to incorporate CQD's onto surfaces in the past, but only using a method called batch-processing, which is much more inefficient and therefore too expensive for mass production. The spray-on method, which Kramer calls sprayLD, uses cheap materials and a simple process that lends itself to general usage.
Although it uses inexpensive, easy-to-find materials, the method does not see a decrease in solar cell efficiency, which is crucial for general adoption: "As quantum dot solar technology advances rapidly in performance, it's important to determine how to scale them and make this new class of solar technologies manufacturable," said Professor Ted Sargent (ECE), Kramer's supervisor. "We were thrilled when this attractively manufacturable spray-coating process also led to superior performance devices showing improved control and purity."
Since the spray can adhere to flexible, filmy material, it can be used to cover- and therefore power- objects of all different shapes and sizes. As of now, the solar cell efficiency is ideal for powering something relatively small, like a tablet, but Kramer believes that in the future it could be used for larger objects that would have more of an impact on the environment. "My dream is that one day you'll have two technicians with Ghostbusters backpacks come to your house and spray your roof."