FROM IEEE Spectrum
Researchers at the London Centre for Nanotechnology at University College London have their sights set on a goal that will make the legions of cellphone users happy: handsets that go a week or more without charging. Eventually, they believe, we might see a phone that never needs to be plugged in. To extend the time between charges, the London group built a prototype device that converts ambient light into electricity using an array of solar cells—made of thin-film hydrogenated amorphous silicon—that’s designed to sit beneath the phone’s screen. The photovoltaic cell takes advantage of the smartphone display’s large footprint. The energy harnessing system also captures much of the light from a typical organic light-emitting diode display that, instead of being projected out of the front of the screen, escapes at the edges, where it is useless.
That will be more complicated that the phone screen will be solar cells at same time as touch screen.