Why can some solar panels generate electricity only in the sun and some in the light? Why is this? Let’s first understand the power generation principle of the solar panel: the sunlight shines on the P-N junction in the solar cell, forming a new hole electron pair. Under the effect of the electric field of the P-N junction, the holes flow from N area to P area, and the electrons flow from P area to N area. After the circuit is connected, a current is formed. It only talks about the sunlight, but it doesn’t say which part of the sunlight. This is why some solar panels can generate electricity in the sun and some can generate electricity in the light. Solar light and light have both similarities and differences. Let’s first understand what part of the solar panel uses to generate electricity.
Sunlight is composed of infrared light, visible light area and ultraviolet light. The wavelength of visible light is 400-760nm, the wavelength of infrared light is greater than 760nm, up to 5300nm, and the wavelength of ultraviolet light is 290-400nm. But what people see is only white light. In fact, it is composed of red, orange, yellow, green, green, blue and purple, which cannot be seen by the naked eye. Take LED light for example, the wavelength range is 460~636nm, and the color is also various. This is the main difference. It is also the principle that solar panels use light to generate electricity. It is mainly the wavelength range that solar panels can absorb.
Optical absorption band of solar cells: single polycrystalline silicon is generally 1100-1200nm, thin film crystalline silicon film is generally 800nm, and some can reach 900nm. Different wavelengths will also affect the conversion efficiency of solar panels, which is why the conversion of solar panels is relatively high at this time in the outdoor at about 1-2 pm (China, summer). Take LED for example, the wavelength is 460-636nm, which is not enough. Also, the test conditions of the solar panel: AM1.51000W/m2 is obtained according to the same principle.
Some data comes from Baidu
If you want to know more about solar panels, please contact us, the solar panel manufacturer – Huanqi Technology (Shenzhen) Co., Ltd.