Sunlight shines on the semiconductor p-n junction to form new hole-electron pairs. Under the action of the p-n junction electric field, the holes flow from the p-region to the n-region, and the electrons flow from the n-region to the p-region. After the circuit is turned on, a current is formed. This is how photoelectric effect solar cells work.
There are two ways of solar power generation, one is light-heat-electricity conversion, and the other is light-electricity direct conversion.
(1) The light-heat-electricity conversion method uses the thermal energy generated by solar radiation to generate electricity. Generally, the solar collector converts the absorbed heat energy into working medium vapor, and then drives the steam turbine to generate electricity. The former process is a light-to-heat conversion process; the latter process is a heat-to-electricity conversion process.
(2) The light-to-electricity direct conversion method uses the photoelectric effect to directly convert solar radiation energy into electrical energy. The basic device for light-to-electricity conversion is a solar cell. A solar cell is a device that converts sunlight energy directly into electrical energy due to the photovoltaic effect. It is a semiconductor photodiode. When the sun shines on the photodiode, the photodiode will convert the sun's light energy into electrical energy, generating current. When many batteries are connected in series or in parallel, it can become a solar cell square array with relatively large output power.