“SE+PERC”单晶硅太阳电池激光掺杂区域的漏电现象研究

RESEARCH ON LEAKAGE PHENOMENON IN LASER DOPED REGION OF“SE+PERC”MONO-Si SOLAR CELLS

在选择性发射极(SE)技术与钝化发射极背接触(PERC)技术相结合(即“SE+PERC”)的单晶硅太阳电池技术路线中,通常采用激光技术进行局部重掺杂,即利用激光的高温特性将硅片表面磷硅玻璃(PSG)层内的磷原子推入硅片内部,形成高低结,从而提高太阳电池的光电转换效率。但是经过激光扫描后的掺杂区域表面的PSG层会被激光损伤,损伤区域在进行碱抛光时常因掩膜的保护性差而被碱溶液腐蚀,导致p-n结被破坏,造成局部严重漏电,从而影响太阳电池的整体电性能。针对“SE+PERC”单晶硅太阳电池制备过程中激光掺杂区域出现的漏电现象,分析了漏电原因,并给出了采用SE激光掺杂工艺及碱抛光工艺时的优化建议。

In the technology route of mono-Si solar cells that combines SE technology with PERC technology(“SE+PERC”),which is usually used for local heavy doping,that is,using the high temperature characteristics of the laser to push the phosphorus atoms in the phosphorus silicon glass(PSG)layer on the silicon wafer surface into the silicon wafer,forming high and low junctions,so as to improve the photoelectric conversion efficiency of the solar cells.However,the PSG layer on the surface of the doped area after laser scanning is damaged by the laser energy.These damaged areas are often rapidly corroded by alkali due to the poor protection of the mask during alkali polishing,resulting in the destruction of the p-n junction,causing serious local leakage,which affects the overall electrical performance of the solar cells.In this paper,according to the leakage in the laser doped area during the preparation of“SE+PERC”mono-Si solar cells,the causes of leakage are analyzed,and suggestions on how to reasonably adopt the SE laser doping process and the alkali polishing process are given.