Little knowledge of solar motion sensor light: When the semiconductor part is illuminated, light-borne free electrons are generated. Under the action of the electric field on the semiconductor side near the joint surface, free electron separation is caused, thereby generating a photovoltaic effect. Not only solar power uses photovoltaic effects, photosensors called photodiodes, but also light-receiving components that are used for fiber-optic communication. In addition, the light-receiving portion of the image used in digital cameras and video cameras also utilizes the photovoltaic effect.