Today, we will introduce the power generation principle of photovoltaic system
If the light is irradiated on the solar cell and absorbed in the interface layer, photons with enough energy can excite electrons from covalent bonds in p-type silicon and n-type silicon, resulting in electron hole pairs. Before recombination, electrons and holes near the interface layer will be separated by the electric field of space charge. The electron moves toward the positively charged n region and the hole to the negatively charged p region. By charge separation in the interface layer, an outward measurable voltage is generated between the P and N regions. At this time, electrodes can be added on both sides of the silicon wafer and connected to the voltmeter. For crystalline silicon solar cells, the typical open circuit voltage is 0.5 ~ 0.6V. The more electron hole pairs produced by illumination, the greater the current. The more light energy absorbed by the interface layer, the larger the area of the interface layer, that is, the greater the current formed in the solar cell.