Between two silicon layers (p-layer boron-and phosphorus-layer n) come with a difference in the number of atoms. Solar light strikes the cell, which emits electrons from the n-layer into the positively charged layer.

The released electrons move through the diode in the negatively charged n-layer. The free electrons are attracted by traces and derived as voltage.

The photovoltaic effect was discovered by random by Edmond Becquerel in 1839. Also by coincidence the commercially relevant principle of the p-n transition was observed.

In 1839,at the ageof 19 years,Becquerelbeganin his father'slaboratory to experiment andbuilt the world'sfirst photovoltaiccell.He works withthe firstbatteryandnoticed thathercurrent flowcan be increasedwith exposure to the sun.