What if you could simply leave your iPhone face-up on a table or windowsill in order to trickle charge it and extend its battery? And what if the same technology that turned its screen into a photovoltaic panel also made its display significantly more efficient than current displays, leading to substantially increased battery life even if you're trapped inside a cave?

That's the promise of a new technology called a "polarizing organic photovoltaic," developed by researchers at UCLA. In order to show you an image on a conventional LCD screen, objects called polarizers must switch on and off to shade the light coming through a screen from a device's backlight. This new kind of polarizer actually harvests the light that would normally be blocked and absorbed, making it 75 percent more efficient than conventional polarizers even when you're in the dark.

Its capability to harvest light means that not only can it recover energy from the phone's backlight, but it can also harvest sunlight and even ambient light — just like those solar powered calculators most of us grew up with.