Research of the solar photovoltaic cells output characteristics influenced by infrared wave in the solar spectrum

Abstract

The energy of solar radiation on the earth mainly concentrates in 0.29~3μm wavelength range, where infrared wave accounts for 53 percent, visible light accounts for 44% and ultraviolet accounts for 3%. For the photovoltaic cells, different light coming from solar radiation has different energy and different penetration depth. For the short waves, the photovoltaic cells have large absorption coefficient and have small absorption coefficient for the long waves. As for the sunlight, if the photon energy is greater than the semiconductor forbidden bandwidth, it will inspire electron-hole pairs, and vice versa. When the range of wavelength is 0.5~1.2μm, silicon photovoltaic cells can transform the light energy into electrical energy and heat energy, and only heat energy to the light which wavelength is greater than 1.2μm. So, the photovoltaic cells will make most of the sunlight change into heat energy, which will influence the characteristics of the photovoltaic cells unless the heat was dissipated in time. In the paper, the thermal battery pasted on the back of the photovoltaic cells is adopted to absorb the heat, so the photovoltaic cells can keep a good state long time. The strategy of energy management is presented in the paper in detail.