Views:0 Author:Site Editor Publish Time: 2021-02-03 Origin:Site
Solar cells, also known as "solar chips" or "photocells", are photoelectric semiconductor sheets that use sunlight to directly generate electricity. As long as it is exposed to light that meets certain illuminance conditions, it can instantly output voltage and generate current when there is a loop. In physics, it is called photovoltaic (Photovoltaic, abbreviated as PV), or photovoltaic for short.
Solar cells are devices that directly convert light energy into electrical energy through photoelectric effect or photochemical effect. Crystalline silicon solar cells that work with the photovoltaic effect are the mainstream, while the implementation of solar cells with thin-film cellsthat work with the photochemical effect is still in its infancy.
The basic characteristics of solar cells have three basic characteristics: the polarity of solar cells, the performance parameters of solar cells, and the volt-ampere characteristics of solar electric environmental protection cells. The specific explanation is as follows:
1. Polarity of solar cells
Silicon solar cells are generally made of P+/N type structure or N+/P type structure. P+ and N+ indicate the conductivity type of the semiconductor material on the front side of the solar cell; N and P indicate the conductivity type of the semiconductor material on the back of the solar cell . The electrical properties of solar cells are related to the characteristics of the semiconductor materials used to make the cells.
2. Performance parameters of solar cells
The performance parameters of solar cells consist of open circuit voltage, short circuit current, maximum output power, fill factor, conversion efficiency, etc. These parameters are a measure of the performance of solar cells.
3. Volt-ampere characteristics of solar cells
The P-N junction solar cell includes a shallow P-N junction formed on the surface, a bar-shaped and finger-shaped front ohmic contact, a back ohmic contact covering the entire back surface, and an anti-reflection layer on the front.
When the battery is exposed to the solar spectrum, photons with energy less than the band gap Eg have no contribution to the battery output. Photons with energy greater than the band gap Eg will contribute energy Eg to the battery output, and energy less than Eg will be consumed in the form of heat. Therefore, in the design and manufacturing process of solar cells, the influence of this part of heat on battery stability and life span must be considered.