Solar cells are devices that respond to light and convert it into electricity.There are many kinds of materials that can produce photovoltaic effect, such as: monocrystalline silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, indium selenide copper and so on.The principle of their electricity generation is basically the same. Now take crystal silicon as an example to describe the process of light power generation.P-type silicon can be doped with phosphorus to form p-n junction.
When light hits the surface of a solar cell, some photons are absorbed by the silicon.The energy of the photon is transferred to the silicon atom, which makes the electron jump to become a free electron and gather on both sides of the p-n junction to form a potential difference. When the external circuit is connected, under the action of the voltage, there will be a current flowing through the external circuit to generate a certain output power.The essence of this process is: the conversion of photon energy into electrical energy.