Solar cells, as their name suggests, are devices capable of converting solar energy into electrical energy.
Solar energy refers to radiant energy from the sun, including light and heat energy. Solar cells enable sustainable energy use by harnessing the energy of light and converting it into electrical energy.
Extension:
The operating principle of solar cells is based on the photoelectric effect. The photoelectric effect means that when light irradiates the surface of a specific material, the energy of the photon excites the material's electrons to a high energy state, generating electron-hole pairs. With proper electric field arrangement, these electrons and holes are separated, producing an electric current.
The main component of solar cells is a semiconductor material, usuallysilicon. Silicon is widely used in solar cells due to its good photoelectric conversion properties. The structure of a solar cell is generally composed of a P-type semiconductor (positive type) and an N-type semiconductor (negative type), and a PN junction is formed between them, also known as the Schottky barrier name. When light irradiates the PN junction, the photon's energy is absorbed, causing electrons to jump from the valence band to the conduction band, thereby generating electron-hole pairs.
In solar cells, one end of the P-type semiconductor is usually doped with a small amount of trivalent elements, such as boron, to form a P-type material. One end of the semiconductor -N-type conductor is usually doped with a small amount of pentavalent elements, such as phosphorus or arsenic, to form an N-type material. N-type materialsP and N type are connected via a PN junction, forming an interface region where electrons and holes are separated. When photons irradiate the PN junction, electrons will be excited to move from P-type material to N-type material, while holes will move from N-type material to P-type material. This movement of electrons and holes creates an electric current, producing direct current.