In the future, smartphones could be powered by invisible solar panels embedded in the device’s screen. But the materials that would make this practically possible are still missing, which makes it difficult to develop such technology. This is because the materials mentioned, which could make the charging plate invisible, would have to be semiconductor layers in order to capture light, convert it into electric current, and power the phone.
Professor Jung-Doon Kim and his colleagues at Incheon University in South Korea suggested that titanium dioxide or nickel oxide could be used. Titanium oxide production is non-toxic and is also capable of absorbing invisible ultraviolet light, allowing visible light to pass through it. Nickel oxide also has increased optical transparency and is the most common element on planet Earth because it can be produced at low temperatures.
The results look promising; more than half of the visible light was able to pass through the battery, giving it a transparent effect with a power conversion factor of 2.1%, a very high figure given that the battery targets only a small portion of the light spectrum, which makes it invisible.
Developing a power cell in a phone screen that uses solar power rather than charging cables could have a beneficial effect on the environment, as well as on the development of a portless smartphone, something many have predicted for years.
Both Samsung and Apple, the two most dominant smartphone manufacturers, have taken steps to remove chargers and headphones from their boxes to protect the environment, while Chinese manufacturer OnePlus has developed a concept phone with disappearing cameras.
In future iPhones, the ports could be completely removed, according to predictions by Apple analyst Ming-Chi Kuo, though this is likely to come from wireless charging rather than solar power.