English
The sunlight shines on the semiconductor p-n junction, forming new hole electron pairs. Under the action of the built-in electric field in the p-n junction, holes flow from the n region to the p region, and electrons flow from the p region to the n region. After connecting the circuit, a current is formed. This is the working principle of photoelectric effect solar cells.
The main specific principle of photovoltaic power generation is the photoelectric effect of semiconductors. When a photon is irradiated on a metal, its energy can be fully absorbed by an electron in the metal. The energy absorbed by the electron is large enough to overcome the internal gravity of the metal and do work, escape from the metal surface, and become a photoelectron. Silicon atoms have four outer electrons. If an atom with five outer electrons, such as phosphorus, is doped into pure silicon, it becomes an N-type semiconductor; If atoms with three outer electrons, such as boron atoms, are doped into pure silicon, a P-type semiconductor is formed. When P-type and N-type are combined together, the contact surface will form a potential difference, becoming a solar cell. When sunlight shines on the P-N junction, holes move from the P pole region to the N pole region, and electrons move from the N pole region to the P pole region, forming an electric current.