by Samantha Englert
An MIT research team has recently developed what is believed to be the thinnest, most lightweight, and flexible photovoltaic cell, with the ability to be installed onto any surface and the potential to charge any portable electronic device. The solar cell is so light that it is able to rest on a soap bubble without the bubble being popped. The real key to this innovation Is a one-process approach in manufacturing the ultra-thin solar cell and the unique substrate that supports it.
After years of experimenting with different methods and materials, the MIT researchers discovered that a flexible polymer, known as parylene, could act as both the substrate that holds the solar cell as well as its coating that protects it from contaminants in the environment. Parylene film is a commonly used plastic coating, similar to the kitchen product, cling-wrap, but only one-tenth its thickness. The entire manufacturing process of sandwiching the parylene around the solar cell and an organic light absorbing material utilizes a vapor deposition technique that takes place in a vacuum chamber held at room temperature without the use of any harsh chemicals. The substrate and the solar cell never need to be handled, thus minimizing exposure to dust or other environmental contaminants that may reduce the cell’s output. These solar cells have also been shown to be extremely efficient in converting sunlight into electricity with an impressive power-to-weight output of 6 watts per gram, about 400 times higher than our current heavier solar sources.
Though years away from commercial production, this new approach to producing feather-light solar cells has the potential to fully power portable electronic devices, such as smart phones, and important implications for maximizing power-to-weight in larger scaled applications, such as aerospace technology.
Chandler, David. 2016. Solar Cells as Light as a Soap Bubble. News.MIT. Feb 25, 2016.