In the future, windows could harvest energy from sunlight and your cellphone could recharge while you're catching some rays in the park. One group of chemists announced this month that they've built a new solar cell that's nearly as transparent as clear glass. While the new solar cells not yet as efficient as the opaque solar panels that are available today, soft, flexible and clear solar cells are working their way through the research stages and could one day be sold in stores.
The new clear solar cells — built by chemists at the University of California, Los Angeles — work by primarily gathering infrared, rather than visible, light. That allows most of the visible light to pass through the cell. The researchers also developed a transparent electrode for the solar cells that is made with silver nanowires.
Several labs are working on windows that create electricity, as InnovationNewsDaily previously reported. Because commercially available solar panels are dark and opaque, homeowners and developers can only install them on the roofs of buildings. Windows that act as solar panels would put more parts of the building to work, generating electricity. One of the greatest challenges for researchers, however, is making solar cells that are both efficient and transparent.
The UCLA solar cells let through two-thirds of the sunlight from outside. At the same time, they convert 4 percent of the energy they gets from the sun into electrical energy. Most commercial solar panels are 11 to 15 percent efficient, according to One Block Off the Grid, a company that advises homeowners on installing solar panels.
The new solar cell is made of polymer materials, which are soft, flexible and cheaper to manufacture than the hard, opaque silicon materials that commercial solar panels use. Right now, however, polymer solar cells are generally less efficient than silicon ones.
The UCLA researchers published their work July 4 in the journal ACS Nano. The same group previously made the world's most efficient solar cells that are made with polymer materials rather than silicon.