Study On Morphology Control Of Monocrystalline Silicon By Copper Particle Assisted Etching

With the rapid development of global economy, the increasing depletion of fossil energy use and GHG emissions and environmental deterioration, the development utilization of renewable energy has become the consensus of future energy development. Solar energy has attracted considerable attention due to its infinite, the advantages of geographical restrictions, free of pollution.In recent years, solar cell technology has gained rapid development under the promoter many countries in the world, however, the higher cost of power generation is still the main reason to hinder its large-scale application. The industry generally believe that 1) reduce the amount of material of the solar cell and the loss,2) improving the conversion efficiency of solar cells are expected to achieve an important means of low-cost photovoltaic power generation.The metal copper nanoparticles assisted chemical etching introduce different micro nano structure on the surface of the monocrystalline silicon, such as nano porous structure, pyramid structure and pyramid nanowire binary composite structure, use of SEM, AFM and UV-vis explore different micro and nano structures, including pore size and reflectivity of the pyramid, analyze the differences and reasons, through regulation and control of the experimental parameters to further improve the absorption efficiency of silicon of solar light.1) The introduction of porous and pyramid structure, to systematically study the effect of the different doping concentration of silicon, the different preparation parameters (sedimentary time of etching, etching liquid ratio, etching time and etching temperature) on porous structure and the pyramid shape. Research shows that: the porosity of the porous structure increases with nano copper particle density, etching time, etching temperature and oxidation agent concentration; the size of the pyramid structure increases with nano copper particle density, etching time, etching temperature and the oxidant concentration. The diameter of pyramid bottom is 0.1～3μm, height is 0.1～2μm. According to the experimental results, the ball and stick model is proposed to explaine the difference of oxidant formation of porous structure and pyramid structure.2) Pyramid and Pyramid-the two element composite nanowire structure optical properties, the effects of different preparation parameters on Pyramid and Pyramid-the two element composite nanowire structure sample reflectance characteristics. The results show that, compared with the 35% single wafer reflectivity, reflectivity of Pyramid structure and Pyramid-nanowire structure composite of samples are obviously reduced, respectively 15% and 5%.