Upcoming Apple smartphones iPhone 6 and iPhone 5S claimed to be more powerful than the previous iPhones.

A new rumour surfaced online claiming that the upcoming Apple smartphones will feature solar cell technology for powering the handsets.

Apple is already using in-cell technology in iPhone 5 dubbed as "integrated touch". But the company wants to explore the technology further to harness solar rays to power the devices when it ran out of battery.

According to PatentlyApple, "Apple is working on this same principle except this time around it's for integrating special solar technology right into future touch displays."

A report claimed that Apple will be using a material called grapheme, which is commonly used in harnessing solar power.

Another reason why the future iPhones are more powerful than its predecessors is because of the upgraded processor that it will include in its specs. Rumour has it that the next generation of iPhone will include an A7 quad core chipset.

On the other hand, Apple is speculated to unleash the two handsets in August of this year and early next year. According to AppleInsider, Chinese company Foxconn, the manufacturer behind most of Apple's products, will exclusively produce the iPhone 6 and iPhone 5S.

Apple are expected to include an improved camera in the iPhone 6 and/or iPhone 5S which is rumoured to be capable of taking "Super HD" pictures. In order to take snaps at that resolution it'll need to have at least a 13 mega-pixel camera.

The lack of NFC support on the iPhone 5 was one of the biggest criticisms aimed at Apple's smartphone. Rumours suggest that the iPhone 5S could include support for the contact-less technology which can be used to pay for items in retail stores. Other features rumoured to be included in the handset is the A7 quad core chip processor, Retina or IGZO screen display among others.