Kyocera has shown a prototype of a mobile phone at the Mobile World Congress in which the screen can partly supply the battery thanks to a transparent layer of solar cells. The technology can also be used for other mobile devices, such as e-readers and feature phones.
The so-called Wysips Crystal technology, in which transparent solar cells are packaged in a 0.1 mm thin layer of foil, was developed by the company Sunpartner. The foil can be placed both in front of and behind the LED panel and would hardly affect the image quality: the layer is 90 percent transparent and the viewing angles are not smaller, according to the manufacturer.
However, the picture is indeed negatively affected by the extra layer, Mobilegeeks noted on the MWC show floor in Barcelona. The solar cells did their job: the phone was continuously charging, unless the user held his hand above the screen. Sunpartner claims that in practice the solar cells can generate 5mW peak per square centimeter, provided there is sufficient light on the screen.
Kyocera and Sunpartner claim that the technology shown can enable ‘infinite’ standby time for smartphones if they receive enough light. However, the solar cells will supply too little power to fully charge an actively used smartphone. Batteries in mobile devices such as e-readers and some feature phones could possibly continue to work without being charged from the mains.