I’d never heard of solar cell phone chargers until I got into this thread, so I did some Googleization....from what I see during my very few minutes, most of ‘em have been “discontinued” - apparently due to virtual worthlessness.
Outdoor outfitters carry solar charging devices for all manner of electronic equipment - and are quite capable of charging cell phones as well as running & charging other devices. Keep googling.
several various solar cell phone charges available at Amazon
And a more specific (though more expensive ..est $71.00) example…
Etón American Red Cross ARCFR600R Solarlink Digital AM/FM/SW/NOAA S.A.M.E. Weather Radio with Flashlight, Siren, Solar and CellPhone Charger (Red) 4-way Power AC/Generator/Battery/Solar
I have several…even for my ‘BOB’ bags