What is the principle of solar energy?

The basic principle of solar energy utilization is the photovoltaic effect. The photovoltaic effect means that when light irradiates the surface of certain materials (such as silicon), photons will excite electrons in the material to jump into the conductive band, generating an electric current. Specifically, a solar panel is made up of many tiny solar cells, each of which is made up of two layers of semiconductor material, usually a p-type silicon layer and an n-type silicon layer.

When sunlight strikes a solar cell, photons excite electrons in the p-type semiconductor, causing them to jump to the n-type semiconductor to form electron-hole pairs. Since p-type semiconductors have positively charged holes and n-type semiconductors have negatively charged electrons, these electrons and holes create an electric field in the solar cell.

If a metal conductor is placed on both sides of the solar cell, electrons will flow under the action of the electric field, forming an electric current. These currents can be output through wires and supplied to various electrical equipment.