Photoelectric conversion refers to the process of converting light energy into electrical energy. It is based on the principle of photoelectric effect. The photoelectric effect refers to the phenomenon where when light shines on the surface of certain substances, the electrons on the irradiated surface absorb the energy of the light and detach from the substance, forming free electrons and generating an electric current.

The key to photoelectric conversion is to use the photoelectric effect to free electrons from atomic binding, thereby forming an electric current. This process involves two main steps: light absorption and electron release.

Firstly, when light shines on the surface of a photosensitive material, the energy of photons is absorbed by the material. During this process, the energy of photons is transferred to electrons in matter, causing them to transition to higher energy levels. This type of energy level transition usually requires the condition of energy conservation, which means that the energy of a photon must match the difference between the electron energy levels in the material.

Next, after the electrons absorb photon energy, if the electron energy exceeds the energy at the bottom of the corresponding conduction band in the material, the electrons can break free, form free electrons, and generate an electric current. This phenomenon becomes the photoelectric effect.

The principle of photoelectric conversion refers to the phenomenon or process of converting light energy into electrical energy. In the process of photoelectric conversion, photoelectric conversion devices such as photodiodes or photocells are usually used.

The working principle of a photodiode is based on the photoelectric effect. The photoelectric effect refers to the phenomenon where when light shines on the surface of a substance, it causes electrons in the substance to gain sufficient energy to transition to the conduction band, forming free electrons and holes. In photodiodes, when light is irradiated at the interface of the PN junction, the light energy excites the charge carriers in the PN junction and forms a current under the action of an external electric field. The magnitude of this current is directly proportional to the intensity of light.

Photocell, also known as solar cell, is a device that can convert solar energy into electrical energy. The working principle of photovoltaic cells mainly relies on the photogenerated voltage effect and photogenerated current effect in the PN junction. When light shines on the PN junction surface of the photovoltaic cell, the energy of photons is absorbed by the material in the photovoltaic cell and converted into the kinetic energy of electrons. These electrons will be separated by the electric field in the PN junction and generate current on the external load. The photogenerated voltage effect refers to the potential difference generated by light irradiation, while the photogenerated current effect refers to the phenomenon of converting light energy into current.