PAPER SOLAR

While you’re up, print me a solar cell; New MIT-developed materials make it possible to produce photovoltaic cells on paper or fabric, nearly as simply as printing a document.
David L. Chandler, July 11, 2011 (MIT News)

"…Almost as cheaply and easily as printing a photo on your inkjet, an inexpensive, simple solar cell [can be] created on [a] flimsy sheet [of paper], formed from special ‘inks’ deposited on the paper. You can even fold it up to slip into a pocket, then unfold it and watch it generating electricity again in the sunlight…

"The technique represents a major departure from the systems used until now to create most solar cells, which require exposing the substrates to potentially damaging conditions, either in the form of liquids or high temperatures. The new printing process uses vapors, not liquids, and temperatures less than 120 degrees Celsius. These “gentle” conditions make it possible to use ordinary untreated paper, cloth or plastic as the substrate…"

A printed solar page (from MIT - click to enlarge)

"It is, to be sure, a bit more complex than just printing out a term paper. In order to create an array of photovoltaic cells on the paper, five layers of material need to be deposited onto the same sheet of paper in successive passes, using a mask (also made of paper) to form the patterns of cells on the surface. And the process has to take place in a vacuum chamber.

"…[It] is essentially the same as the one used to make the silvery lining in [a] bag of potato chips: a vapor-deposition process that can be carried out inexpensively on a vast commercial scale…"