Photoelectric properties of solar cells
Back
2022/11/07 13:55:06
Solar cells generate electricity based on the photoelectric properties of special materials. Boldface (such as sunlight) radiation comes from radio waves of different wavelengths (matched to different frequencies), such as infrared sensing, ultraviolet light, and visible light. When this ray shines on a different conductor or semiconductor, the photons interact with the free electrons in the conductor or semiconductor to create an electric current.
The smaller the wavelength and the higher the frequency of the ray, the higher the kinetic energy. For example, the kinetic energy of ultraviolet light is much higher than that of infrared sensing. However, not all the kinetic energy of rays of all wavelengths can be converted into electromagnetic energy. It is worth noting that the photovoltaic effect is independent of the intensity and size of the rays. Only when the frequency reaches or exceeds the threshold that can cause the photovoltaic effect, the current can be caused.
For example, the band gap of crystalline silicon is about 1.155eV at indoor temperature. Therefore, only a light source with wavelength lower than 1100nm can make crystalline silicon cause photovoltaic effect. Solar cell power generation is a renewable environmental protection power generation method, the whole process of power generation is not easy to cause carbon dioxide and other air pollutants, not easy to cause environmental pollution to the natural environment.
According to the materials, it is divided into silicon semiconductor rechargeable battery, CdTe thin film battery, CIGS thin film battery, dye sensitized thin film battery, organic material rechargeable battery, etc. The silicon cell is divided into single crystal rechargeable battery, polycrystal rechargeable battery and amorphous silicon thin film battery. For solar cells, the most important main parameter is the conversion efficiency. Among the silicon based solar cells developed in the laboratory, the efficiency of single crystal silicon cell is 25.0%, the efficiency of photovoltaic cell is 20.4%, the efficiency of CIGS thin film cell is 19.6%, and the efficiency of CdTe thin film cell is 16.7%. The efficiency of amorphous silicon (amorphous silicon) thin film cell is 10.1%.
Previous
