As the intensity of the light falls, because of clouds or whatever, solar cell output also falls. The cell's current is more sensitive to the light intensity than the voltage is. The light intensity can also be reduced just by twisting the cell. The output of a solar cell is at its maximum when it is perpendicular to the incident light beam, i.e. when it is pointed at the sun. Photons Photons are what make up the light we see.
Light is an electromagnetic wave that is transmitted in short pulses of energy.
These short pulses of energy are referred to as photons. Semiconductors A semiconductor is a type of material. The chips used in electronics are made of semiconductor materials, and so are photovoltaic cells. The most common semiconductor is silicon. When a photon hits a silicon atom it gives an electron within the atom enough energy to leave it and move off through the structure.