Study Of Laser Scribing Technology And Equipment Optimization For A-Si:H Thin Film Solar Cells

The renewable energy is becoming the research hotspot due to the global energy crisis and environmental pollution problems.As we know,solar energy is one of ideal clean energy.Therefore,it is urgent to research and develop cheaper and more efficient solar cells.The a-Si: H thin film solar cell has become an important member of the solar cells family because of its high efficiency in weak light,high light absorption,low cost and suitable for large area production.Laser scribing is an important technology of a-Si: H thin film solar cells.It will affect the conversion efficiency of solar cells.The paper discussed the process of laser scribing,analyed the influence of the parasitic resistance on the solar cells' power.We optimized the parameters of the laser,and obtained the optimum parameters.We studied the influence of small battery with negative edge on solar cells,then,optimized the laser scribing process.Finaly,we reduced the dead area of solar cells after optimizing the process and equipments.Main contents and conclusions in the paper are listed as follows:1.The influence of parasitic resistance on the conversion efficiency of solar cells: the output power,filling factor and conversion efficiency of the solar cells decrease with the increase of the series resistance,and increase with the increase of the parallel resistance.Then the influence of laser scribing on series resistance and parallel resistance of solar cel s is analyzed.2.We explored the best laser scribing process parameters of P1,P2,P3 and P4.The process is verified: the maximum power is up to 73 W,the conversion efficiency is 9.7%,and the fill factor is 0.728.3.Use the technology of insulation line in P1 to replace the technology of mask tape before P2,and the process was verified and compared.The power for the two processes is almost the same.The production cost is reduced by introducing the P1 engraving insulation technology.4.We studied the influence of small battery with negative side on the solar cells' power,and concluded that the small battery on the negative side will reduce the overall power of the solar cells.So we put forward the new process that we don't carve the last laser line in P2 and P3.Therefore,the small battery on the negative side was invalid.And process validation: the solar cells' power increased by 1.2W,tact time of P2 and P3 also decreased by 3~4s.5.To improve the power of the solar cells,we decreased dead area by 30?m through optimizing the P1 line width and decreasing the line distance of P1-P2 & P1-P3.And process validation: the solar cells' power increased by 0.26 W,the average power is more than 74 W,and the conversion efficiency is more than 10%.