Study On The Application Of Solid Laser In The Manufacture Of Crystalline Silicon Solar Cells

With the continuous development of laser technology,laser equipment has been solve many problems that can’t solved by nomal technology.In many kinds of laser that solid lasers have many advantages including firm structure,strong stability,excellent thermal performance and mechanical properties,which make it particularly suitable for the fabrication of solar cells.It can meet the industries demandsof low cost on production and excellent performance ofthe solar cells with that solid laser ablated the passivation layer on silicon back surface.However,inappropriate laser ablation also lead damage on the solar cells.For example,the excessive laser energy ablated the surface of the Si Nx layer,the overplus heat energy would transfer to the silicon substrate and change the microstructural on silicon surfaces.Whileif the laser power is too small to remove the deposition layer,that will lead the reducingphotoelectric conversion efficiency of solar cells.Firstly,optimizationthe best parameters of solid lasers.In the view of the different work parameters of the laserwill lead different effects of solar cells.The samples whichprocess with the same conditions are ablated by solid laser.Regulated the laser power,scanning speed,single pulse repetition frequency based on the theoretical calculation and experiment.Secondly,through the passivation technology to reduce the silicon carrier surface recombination rate,improve the solar cells performance.Compared the effect of Si Nx film,Al₂O₃ thin film and Al₂O₃ / Si Nx stack film passivated on the silicon film back surface after laser ablation.Thirdly,determine the best technology of localized back contact with solid laser ablation.In the one hand,the Si Nx stack was passivated on the sicicon and ablated by laser which power is 70%,and the cell efficiency is 17.05%.On the other hand,the Al₂O₃ / Si Nx stack was passivated on the silicon wafer back surface,and ablated by solid-state laser,which received best efficiency 19.20%.In summary,it is very important to explore the best parameters and the corresponding process of solid lasers in the manufacture of crystalline silicon solar cells.