New transparent solar cells can be used on windows, smartphone screens

This new type of transparent solar cell can be used to cover windows, buildings or smartphone screens to produce solar energy.

Named a transparent luminescent solar concentrator and developed by researchers in Michigan State University in the US, this material can be used to cover anything that has a flat, clear surface. Transparent solar cell technology has been attempted before, but the energy the cells produced was poor and the materials they were made out of were highly coloured.

"No one wants to sit behind coloured glass,” said one of the researchers behind the technology, chemical engineer Richard Lunt, in a press release . "It makes for a very colourful environment, like working in a disco. We take an approach where we actually make the luminescent active layer itself transparent.”

The new transparent solar cells are made from tiny organic molecules that absorb invisible wavelengths of sunlight such as ultraviolet and near infrared light. This invisble light is then guided to the edge of the solar panel, where thin strips of photovoltaic solar cells pick it up and convert it into energy. "Because the materials do not absorb or emit light in the visible spectrum, they look exceptionally transparent to the human eye," Lunt said.

Not only are they transparent, these solar cells are also flexible. The researchers are now working on scaling the technology up for commercial applications such as window coverings for residential and office buildings, smartphone and tablet screens, electronic signs, and car windows.

"It opens a lot of area to deploy solar energy in a non-intrusive way,” said Lunt. "It can be used on tall buildings with lots of windows or any kind of mobile device that demands high aesthetic quality like a phone or e-reader. Ultimately we want to make solar harvesting surfaces that you do not even know are there."