Research On A New Texturing Technique Of Monocrystalline Silicon Solar Cells

Surface texturization for monocrystalline silicon is important procedure in silicon solar cells production. According to the anisotropic corrosion mechanism of monocrystalline silicon, we can achieve pyramidal microstructures on the surface of solar cells by means of chemical etching technique. As the pyramidal structure can reduce the surface reflectance of solar cells and increase the current density of photo-generated carriers, we can achieve the goals of increasing the solar cell's conversion efficiency and reducing the production cost. This paper is to investigate a new texturing technique with the mixed solution of sodium hypochlorite and CHTH(Cyclohexanedimethanol). This solution can be used to texture monocrystalline silicon surface, and the advantage of this texturization is that it can form pyramidal structures on the silicon surface, whose size is relatively smaller. With a UV-3150 spectrometer measurement, the average surface reflectance of silicon textured with the new technique is reduced to 12.5% in the wavelength spectrum of 450-1000nm. Furthermore. this new technique uses one step texturization instead of two steps of other techniques and reduces three procedures. The chemical reaction products with this new method are environment friendly. Therefore, this new texturization technique is possibly promising to reduce the production cost and improve the solar cells'efficiency.In the first chapter, we summarize the PV industry development of the world and our country. And we also elaborate the current research situation of crystalline silicon solar cells. Finally we illustrate the significance, innovation and major tasks of this research.In the second chapter, texturization techniques for monocrystalline silicon solar cells and multicrystalline silicon solar cells are explained. respectively.Finally, we investigate the new texturing technique, that includes the component of texturing solution (sodium hypochlorite and CHTH). the texturization of silicon surface, and the comparison of this new technique and the conventional technique. At the beginning, we illustrate the texturization process of monocrystalline silicon solar cells. Then some potential advantages of this new technique are also concluded. Moreover, we discuss the chemical reaction principles, the influence of several experimental parameters, such as the concentration of solutions, texturing time and reaction temperature. In addition, we take two solutions, the solution of sodium hypochlorite with CHTH and the solution of sodium hypochlorite with ethanol, as a comparison in texturing results. At last, we analyze the existing problems, propose its corresponding solutions and summarize the new technique's advantages.