Sunny Future for Transparent Solar Cells

Tired of carrying a spare battery for your smart phone? Relief may be on the way thanks to advances in transparent solar cell technology.

Imagine charging your phone, without using a charger. That’s the reality before us if American researchers have their way. University of California scientists have developed a new type of solar cell, made from a new polymer. The polymer lets through 66 per cent of light at a wavelength of 550nm, and around 60 per cent of the rest of the visible spectrum.

This could one day pave the way for the installation of transparent solar cells in smart phone screens, letting them remain charged without wires, or built into windows to power our homes. It wouldn’t be the first time windows have been used to gather power – others have played with coatings that trap light and direct it to solar cells in the edge of the pane – but it is the first time the window itself could be the photovoltaic cell.

 Sunny Future for Transparent Solar Cells

Okay, so what makes this different? According to lead researcher Yang Yang, the key is the top layer, which is an electrode constructed by laying down titanium dioxide, coating it with a network of tiny silver wires, and filling in the gaps with nanoparticles of indium tin oxide. The method of production, solution processing, could lead to cells being manufactured on a large scale, similar to a printing press for photovoltaic cells.

It’s not a walk in the park, mind you. Polymer solar cell technology, while potentially cheaper than conventional silicon cells, has a less desirable efficiency record. Additionally, the efforts to make them transparent have reduced this even further, with Yang’s cells converting light into electricity with 4 per cent efficiency. Compare this to regular polymer cells at around 10 per cent, and standard silicon cells converting at 40 per cent efficiency and you can see that the road ahead is long.

Be that the case may, but the long walk down this road is underway.