Preparation Of Optical Thin Films By Electron Beam Evaporation

Optical thin films are used everywhere,from daily life to national armaments,and they fill every aspect of our lives and make our lives more colorful,among which,as the optical thin film with the widest range of applications and the highest usage rate,optical thin films play an immeasurably important role.As the global population increases year by year,the demand of human society for energy continues to grow,relying on nonrenewable energy sources is not a long-term solution.If you want to improve solar energy utilization,you have to improve the photoelectric conversion efficiency of the solar cell,and by coating the surface of the solar cell with an anti-reflective film,you can increase the solar cell's more light transmission and reduce the reflectance of light,thus achieving the effect of improving the photoelectric conversion efficiency.At the same time,a concave and convex structure is constructed on the surface of the solar cell to make the light refract multiple times,increasing the light range and the utilization efficiency of the light on the surface,which is also one of the important ways to improve the photoelectric conversion efficiency of the solar cell.In this paper,the study of polysilicon surface texturing under strong magnetic fields and the preparation of anti-reflective films by electron-beam evaporation to reduce the surface reflectance of polysilicon wafers,mainly consisting of the following:(1)The reflectance curves of single-layer,double-layer,triple-layer,quad-layer,and six-layer films were simulated and optimized automatically by Essential Macleod,and the thicknesses of the four-layer and six-layer films were optimized locally by the simplex method.(2)Under the action of non-magnetic field and 1T,2T,3T,4T magnetic field,the wafer was etched in Na OH solution at a temperature of 80°C with a concentration of 10%for 10 minutes,and the experimental results showed that with the increase of magnetic field strength,the degree of corrosion of polysilicon wafer was enhanced,the surface texture of polysilicon became more delicate,and the reflectivity of wafer was reduced to15% at 4T magnetic induction strength.(3)The ZSS-800 chamber vacuum coater was used to coat different film systems on the etched silicon wafer to verify the theoretical design results of the films and the correctness of the software simulation results.The results show that among all the film systems,the six-layer film has the most significant effect on the actual anti-reflection,with an average reflectance of 3.92% in the visible range,which meets the design requirements.From the surface topography,we can see that with the increase of film layers,the surface texture of the wafer becomes less and less obvious,and the film coverage is more uniform.