The Photovoltaic Effect

The photovoltaic effect is the conversion of light into electrical energy. It's a process that occurs when light hits a material, such as a semiconductor, causing the electrons in that material to become excited and flow through an external circuit.

In a semiconductor, there are two types of electrons: valence electrons and conduction electrons. Valence electrons are tightly bound to the atoms in the material and are not free to flow. Conduction electrons, on the other hand, are free to move within the material and are responsible for its electrical conductivity.