Reduction Of Reflection In The Amorphous Silicon Thin Film Solar Cell With Grating Structure

As a clean,cheap and sustainable new energy.solar energy get more and more universal importance, solar cells of amorphous silicon thin film deposited on a single crystal have a high efficiency. Subwavelength grating structure on the surface of silicon can reduce reflectivity of solar and multilayer antireflection coatings can increase the broadband transmission. With the development of binary optics and microelectronics processing technology, the phase grating already can be made up by interference exposure method, laser direct writing and electron beam direct writing.The following works are completed in the thesis:Some basic knowledge, research status at home and abroad of solar cells are introduced in chapter one. Because of centering on reducing broadband reflectivity of solar cells by using Fresne zone plate, so we introduce theory and research status at home and abroad of Fresne zone plate and COMSOL Multiphysics in chapter two. The third and fourth chapters are the main part of the paper, showing the results of our study. In the third chapter, a new amorphous silicon film solar cell structure is designed, where the antireflective coating consists of double layer gratings. The Si film is etched into the array of Fresnel zone plate (nonperiodic grating) structure to focus light to the amorphous silicon film. The ITO film on Si is etched into a subwavelength and nonperiodic grating array. The designed double grating antireflective film can reduce refraction and increase the broadband transmission of light. The intensity distribution of reflection and transmission fields are simulated by using the FDTD method. In the fourth chapter, we designed the solar cell structure with a circular single anti-reflection film on the amorphous silicon thin film. The grating anti-reflection film structure contains one siliceous round Fresnel zone plate structure and one Fresnel zone of ITO plate structure. The proposed structure has a high broadband transmission and the ability to focus sunlight to solar cells. Conclusions and prospects are given in the fifth chapter.