That sounds like a solar panel; more specifically, a photovoltaic panel.
phototcell
phototcell
phototcell
phototcell
phototcell
phototcell
Solar cell.
Photovoltaic Cells (PV)
This would be called a photocell.
This would be called a photocell.
This would be called a photocell.
This would be called a photocell.