Why no solar panels on phones? | Free Charging

Since childhood when we have started using Calculator where at the top we used to have the solar panels.

We might have thought why can't we also have a Solar panels on our smart phones. So many of them has thought of fixing the solar panels on the back side of the phone so they thought that it might get so easy that we never have to charge our phones as it would get so better.But still now why dint we do this work and what is the current scenario of this topic so today we will discuss on this topic briefly ......

But before starting this topic i would like to say that it is not the thing that people has not experimented the solar panel on the back side but people has done in several time and has failed ...
So their was a phone we are almost talking about 10 years ago when Samsung brought a phone E1107.

This phone was launched in India and it was a feature phone it had a Solar panel at the back side of the phone but it does not mean that we do not have to charge but If you would keep that phone near the sun for about 1 hour than it would give 5- 10 mins more talk time. Than again Samsung launched a phone named Samsung Blue earth
This phone was almost launched world wide with the sme feature of charging it for about 1 hour and get 5 - 10 mins extra talktime.
Than after few years even L.G. brings out with their solar panel phone LG Pop

But the phone was a big flop..
Because the power generator was not sufficient to full fill the needs of our phone.
Then after research went on and on and even Nokia also thought of launching but then Nokia thought that the idea is not physible.
After few years maybe in early 2012 even puma launched their Solar panel phonewhich was also a big flop.
From the past two years MWC sun Cairo technology is going to bring a phone and they show that it is prototype and solar panel phones can be used for a long time in future. So is this actually possible friends ?
So some of the company are busy researching and they are planning to bring a Solar phone maybe after 2years 5 years or even more but it will come in a short time maybe.
Resteem Upvote and Comment your thoughts .