The so-called photo-attenuation refers to the phenomenon that the power of the solar cell is lowered due to the irradiation of sunlight. Photovoltaic attenuation of solar panel photovoltaic modules can be divided into two phases: initial photoinduced attenuation and aging attenuation.
1. Initial photoinduced attenuation
The initial photoinduced attenuation, that is, the output power of the solar panel photovoltaic module, decreased significantly during the first few days of use, but then stabilized. The main reason for this phenomenon is that the boron-oxygen complex in the P-type (boron-doped) crystalline silicon wafer reduces the minority carrier lifetime.
By changing the P-type dopant, replacing the boron with the crop can effectively reduce the photo-induced attenuation; or pre-illuminating the cell, so that the initial photo-induced attenuation of the cell occurs before the component is manufactured, and the initial photo-induced attenuation of the photovoltaic module It can be controlled within a small range while also improving the output stability of the component. Photo-induced attenuation is more related to cell manufacturers. The significance for component manufacturers is to select high-quality cells to reduce the effects of photo-induced attenuation.
2. Aging decay
Aging decay refers to the extremely slow power drop that occurs during long-term use, which is related to the slow decay of the battery and to the degradation of the performance of the package material. Among them, the irradiation of ultraviolet light is the main cause of the degradation of the main material properties of the components. Long-term exposure to ultraviolet light causes aging and yellowing of EVA and backsheet (TPE structure), resulting in a decrease in light transmittance of the module, which in turn causes a decrease in power. This requires component manufacturers to strictly control the choice of EVA and backplane. The selected materials must be excellent in aging resistance to reduce component power attenuation caused by aging of auxiliary materials.