激光掺杂制作选择性发射极晶体硅PERC电池的工艺研究

Process Research on Fabrication of Selective Emitter Crystalline Silicon PERC by Laser Doping

基于PERC (Passivated emitter and rear cell)电池的工艺基础,进行了激光掺杂制作选择性发射极晶体硅PERC电池的研究。以现有的PERC电池制造技术路线为基础,激光掺杂制作选择性发射极。研究了经激光掺杂后,选择性发射极对方块电阻、磷扩散结深及表面掺杂浓度、遮光比、激光能量密度、激光脉冲重叠率的影响。利用四探针测量仪、电化学电容-电压法(ECV)、扫描电子显微镜(SEM)、WT2000(μPCD-microwave photo conductivity decay)、二次离子质谱测量仪(SIMS)、WCT120测试仪、光致发光光谱仪(PL)、光谱响应(EQE)、二次元测长仪(Two dimensional length measuring instrument)对试样依次进行了表征。研究结果表明:激光掺杂后的PERC电池在短波波段具有更高的量子效率。方块电阻主要影响了PERC电池的表面复合速率。而PERC电池的开路电压主要取决于方块电阻、激光能量密度、激光脉冲重叠率。短路电流密度主要取决于方块电阻、磷扩散结深及表面掺杂浓度、遮光比、激光能量密度、激光脉冲重叠率。

Based on the process basis of PERC(passivated emitter and rear cell)cells,laser doping was performed to fabricate selective emitter crystalline silicon PERC cells.On account of the existing PERC battery manufacturing technology route,the selective emitters were fabricated via laser doping.The effects of selective emitter on the sheet resistance,phosphorus diffusion depth and surface doping concentration,shading ratio,laser energy density and laser pulse overlap rate after laser doping were studied.The samples were characterized through four-probe measuring instrument,electrochemical capacitance-voltage method(ECV),scanning electron microscope(SEM),WT2000(μPCD-microwave photo conductivity decay),secondary ion mass spectrometer(SIMS),WCT120 tester,photoluminescence(PL),spectral response(EQE),and two dimensional length measuring instrument.The results indicated that the laser-doped PERC battery has higher quantum efficiency in the short-wavelength band.The sheet resistance mainly affects the surface recombination rate of the PERC battery.The open circuit voltage of the PERC battery mainly depends on the sheet resistance,the laser energy density,and the laser pulse overlap rate.The short-circuit current density mainly depends on the sheet resistance,the phosphorus diffusion junction depth and the surface doping concentration,the shading ratio,the laser energy density,and the laser pulse overlap ratio.