Why do some solar panels produce electricity only in sunlight and others in light?

Why do some solar panels produce electricity only in sunlight and others in light? Why is that? Let's first understand the power generation principle of the solar panel: sunlight shines on the P-N junction in the solar cell, forming a new hole-electron pair. Under the action of the electric field of the P-N junction, holes flow from the N region to the P region, and electrons flow from the P region to the N region. After connecting the circuit, current is formed. It only says the sun's rays, but it doesn't say what part of the sun's rays, which is why some solar panels can generate electricity from sunlight and some from light. There are both similarities and differences between sunlight and light, so let's take a look at that and see what part of the light a solar panel uses to generate electricity.

28418a1be54c6d30066725f5dccaffb4Sunlight is composed of infrared light, visible light and ultraviolet light. The wavelength of visible light is 400 ~ 760nm, the wavelength of infrared light is greater than 760nm, the longest is 5 300nm, and the wavelength of ultraviolet light is 290 ~ 400nm. But what people see is white light, which is actually a combination of red, orange, yellow, green, cyan, blue, and purple, which is invisible to the naked eye. Leds, for example, range in wavelength from 460 to 636nm and come in a variety of colors. This is the main difference, and this is how solar panels and solar cabling use light to generate electricity, mainly the range of wavelengths that solar panels can absorb.

The light absorption band of solar cells: single polycrystalline silicon is generally 1100-1200nm, thin film crystalline silicon is generally 800nm, and some can reach 900nm. Different wavelengths will also affect the conversion efficiency of solar panels, which is why solar panels have high conversion at around 1-2 PM outdoors (summer in China). Take the LED as an example, the wavelength is between 460 and 636nm, this light can not be satisfied. ​Also, the solar panel test conditions: AM1.5, 1000W/㎡ is also based on the same principle.

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