Researchers at MIT have successfully manufactured the world’s thinnest and lightest solar cell. This cell is so tiny that it could be placed on a soap bubble without popping it. That’s quite a feat and it also means that such cells could be attached to virtually any surface where they could then generate clean, renewable energy.
According to MIT professor and associate dean for innovation Vladimir Bulović, the key to their success in creating this innovative cell lies in the special production technique they developed, which calls for the making of the solar cell, the substrate and its protective overcoating in a single process. The latter also takes place in a vacuum chamber in order to prevent dust and other contaminants from adhering to it.
To create the substrate and overcoating of the prototype solar cell they used a flexible polymer called parylene, which is quite common. For the light-absorbing layer they used an organic material called DBP. Next, the solar cell and substrate are created using vapor deposition. This technique makes it possible for the solar cells to be created without the need for harsh chemical solvents, or high temperatures. The solar cells thus produced are only about two micrometers thick and very flexible
The prototype cell they made is just proof-of-concept at this stage and is not very efficient as a result. However, due to how lightweight it is, it does have the highest power-to-weight ratio ever achieved. To put that into perspective, a silicon-based solar cell produces about 15 watts per kilogram while this new, thin solar cell can produce 6 watts per gram.
According to the researchers, these cells could be made from a variety of materials. The real innovation lies in the manufacturing process. By perfecting and commercializing it, solar cells could one day be attached to just about nay surface, including shirts, notebooks and so on, where they would harvest solar power and be virtually invisible. The technology still needs a lot of work though, so this could take a while yet.