Preparation And Optical Properties Of Silicon Based Surface Microstructure

As the global energy crisis and environmental pollution become more and more serious,new form of energy resources,especially solar energy,are increasingly attracting the attention from researchers.However,the conversion efficiency of solar energy still needs to be improved.In order to improve the solar energy conversion efficiency,the main research direction is the preparation of surface textures and the characterization of their optical properties at present.In this paper,the nanoporous silicon structure was prepared by double-groove electrochemical etching.The SEM,luminous intensity,reflectivity,and transmittance of the prepared sample were tested.The effects of different electrolyte ratios(ethanol and hydrofluoric acid),different electrolysis times,and different electrolyte current densities on the surface morphology and optical properties of porous silicon structures were investigated to optimize the preparation process of porous silicon.Finally,the prepared nanoporous structure is copied to the surface of the solar cell by the template method,so that a nanoporous structure film canbe formed on the surface of the solar cell.Scanning electron microscopy was used to observe the structural features formed on the surface of the silicon wafer under different process conditions and the structural morphology of the thin film copied onto the surface of the solar cell,ultraviolet infrared spectrophotometer and fluorescence spectrophotometer were used to detect the optical properties of the surface structure of the sample,so as to obtain the best preparation process,then verify the results with PV performance testing.Finally,the optical properties and the nature of the nanoporous silicon structure were theoretically demonstrated by simulation software.The results show that different nano-porous silicon structures formed on the surface of silicon wafers will be different in different preparation processes.The luminescence intensity also shows a tendency of rising first and then decreasing with the change of the electrolyte concentration,the change of the current density,and the change of the electrolysis time,and the reflectivity and the light transmittance also change regularly with the conditions,the optimum preparation conditions were as follows:electrolyte concentration ratio was 1:1 ratio of ethanol to hydrofluoric acid,electrolysis time was 120 min,and electrolytic current density was60 m A/cm2.Through the further testing of the photovoltaic test,the best open circuit voltage and power are obtained.The template method can be used to replicate the nanoporous silicon structure prepared by the bestprocess on the solar cell surface film,through the test of optical properties,it can be concluded that the nanoporous structure can be successfully replicated to the surface of solar cells.Finally,the FDTD Solution software was used to simulate and theoretically prove that the micro-nano structure can improve the efficiency of solar energy absorption and utilization.In general,the nanoporous silicon structure can reduce the reflectance of light and enhance the absorption and utilization of light.