Green Machine: Transparent solar cells could come cheap

Hal Hodson, technology reporter

(Image: UCLA)

Windows and smartphone screens may soon come with built in solar power, letting through visible light while gathering energy from other parts of the spectrum.

Researchers led by Yang Yang at the University of California, Los Angeles have built a new type of polymer solar cell which lets through 66 per cent of light at a wavelength of 550 nanometres - green light - and about 60 per cent for the rest of visible spectrum.

The key component of the cell is the top layer - an electrode built by spraying a network of silver nanowires onto a layer of titanium dioxide, then filing in the gaps with nanoparticles of indium tin oxide.

It's not the first time solar cells have been built into windows - other efforts have explored adding a coating to windows which traps light inside and directs it to photovoltaic cells at the edge of the pane.

But Yang's production method, known as solution processing, is unique in that it could open the door for making the cells on a large scale using "roll-to-roll" manufacturing techniques - much the same way newspapers are printed on paper.

Polymer solar cells are gaining attention for solar power generation because of their potential to be mass produced more cheaply than traditional silicon photovoltaic cells. However, the efficiency record for turning light into electricity currently stands at 40 per cent for silicon-based cells, while the record for PSCs is just 10.4 per cent, with trade-offs for transparency bringing Yang's efficiency down to 4 per cent.

Source: http://feeds.newscientist.com/c/749/f/10897/s/21f33965/l/0L0Snewscientist0N0Cblogs0Conepercent0C20A120C0A80Cgreen0Emachine0Etransparent0Esola0Bhtml0DDCMP0FOTC0Erss0Gnsref0Fonline0Enews/story01.htm

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