Last year Apple signed a $578m contract with GT Advanced Technologies, a company that processes the sapphire.
Analyst Matt Margolis from Seeking Alpha came to the conclusion that the sapphire crystal display of the future iPhone can be combined with solar cells, a move that could increase the battery life of the device.
The acquisition of patents on solar energy, the publication of specific job offers and special equipment control strongly suggest that Apple would seek to integrate solar cells in their screens, he argues.
Apple already uses sapphire crystals on the iPhone – to cover the camera lens and the TouchID in the Home button on the iPhone 5S.
A recent report claimed that Apple has started testing screens made of sapphire crystal.