Do telephones use solar cells?

No. They could but more home phones use a battery of some sort if it has a cordless headset and if it doesn't it is plugged into the wall with a charger. So many things could use solar cells that don't. I don't know of one cell phone that uses a solar cell and it could. Recently Prius came out with a fan system that uses solar cells on the roof of the car. Why haven't we had this before? It has been around, but we only seem to use it putting lights on in the yard or on the roof of a house.