The mostly widely used substrate, or support material, for solar cells today is glass. Now, a new technology developed by a team of researchers at MIT allows solar cells to be printed on inexpensive and readily available substrates, like paper - almost as cheap as printing a photograph. This ability to print solar cells on paper also poses a significant weight advantage for shipping.
According to an article on MIT News, the new technique is very different from the standard methodology for creating solar cells in that it doesn’t use liquids or high temperatures. Instead, vapors are used to deposit the materials onto the substrate, allowing for the use of a wider variety of materials. (Vapor-deposition is the technique also used to line potato chip bags with that thin silver layer.) The layers of materials are printed one on top of the other onto the substrate.
The paper in Advanced Materials is co-authored by MIT professors Karen Gleason and Vladimir Bulović, graduate student Miles Barr, and six others. The paper solar cell they’ve developed can even be folded up and when unfolded, still produce electricity. The resilience of these solar cells was further demonstrated by printing one onto a sheet of PET plastic, then folding and unfolding it 1,000 times, and they were still able to wire it up to produce electricity. The cells have even been shown to work after being run through a laser printer, thus being exposed to the heat of the toner-fusing process.
Reality check: it should be noted that the solar cells produced by this method so far are only 1% efficient. Current silicon solar cell technology is approaching 30% efficiency. Nevertheless, work continues to make these new flexible solar cells more efficient so that they may be put to practical use.