① After the solar cell absorbs photons of a certain energy, an electron-hole pair is generated in the semiconductor, which is called "photogenerated carriers". The two have opposite polarities, electrons are negatively charged and holes are positively charged.

② Photogenerated carriers with opposite polarities are separated by the electrostatic field generated by the semiconductor PN junction.

③ Photogenerated current carriers, electrons and holes, are collected by the positive and negative electrodes of the solar cell respectively, and current is generated in the external circuit, thereby obtaining electrical energy.