The few carrier holes diffused to t

The few carrier holes diffused to the interface will be pulled to the p region by the built-in electric field, while the few carrier electrons diffused to the interface will be pulled to the n region by the built-in electric field, the Electron Hole Pairs generated in the junction region are pulled towards the N and p regions respectively by the built-in electric field. When the external circuit is open, these photoelectrons and holes will accumulate in the vicinity of the PN junction, resulting in an additional positive charge in the p region and an additional negative charge in the n region, resulting in a photoelectromotive force on the PN junction. This phenomenon is called the photovoltaic effect, also known as the photovoltaic effect, solar cells are based on the photovoltaic effect.