A solar cell is a device that responds to light and converts light energy into electricity. There are many kinds of materials that can produce photovoltaic effect, such as: single crystal silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, indium selenium copper and so on. Their power generation principles are basically the same, and the photoelectric power generation process is described by taking crystalline silicon as an example. P-type crystalline silicon can be doped with phosphorus to obtain N-type silicon, forming a P-N junction.
When the light shines on the surface of the solar cell, some photons are absorbed by the silicon material; the energy of the photons is transferred to the silicon atoms, causing the electrons to transition and become free electrons to gather on both sides of the P-N junction to form a potential difference. When the external circuit is connected , under the action of this voltage, there will be a current flowing through the external circuit to generate a certain output power. The essence of this process is: the process of converting photon energy into electrical energy.