激光诱导烧结对TOPCon太阳电池接触性能影响  

Influence of laser induced sintering on contact performance of TOPCon solar cells

作　　者：谢一博 方超炎 陈德爽 何悦 黄仕华[1] Xie Yi-Bo;Fang Chao-Yan;Chen De-Shuang;He Yue;Huang Shi-Hua(College of Physics and Electronic Information Engineering,Zhejiang Normal University,Jinhua 321004,China;Hengdian Group DMEGC Magnetics Co.,Ltd.,Jinhua 322118,China)

机构地区：[1]浙江师范大学物理与电子信息工程学院,金华321004 [2]横店集团东磁股份有限公司,金华322118

出　　处：《物理学报》2024年第24期249-261,共13页Acta Physica Sinica

基　　金：浙江省重点研发计划(批准号:2021C01006)资助的课题.

摘　　要：激光诱导烧结又称为激光增强接触优化(LECO),可以显著降低TOPCon太阳电池金属电极与硅之间的接触电阻,提高电池效率.首先,本文研究了反向偏压、激光强度等LECO工艺参数对TOPCon电池性能的影响,并对其影响机理进行了详细的讨论与分析.其次,研究了二次高温烧结与二次LECO工艺对电池性能的影响.当二次烧结温度从280℃升高至680℃时,电池效率从26.35%急剧下降至1.3%.但是,对经过二次高温烧结的电池片再进行二次LECO处理,电池效率可以恢复到二次高温烧结前的水平.采用改良后的纯银浆料制备的TOPCon电池,在没有经过LECO处理之前,由于银电极与硅没有形成有效的金属半导体接触,电池平均效率只有0.02%.经过LECO处理后,使用纯银浆料的电池效率提升至26.35%,比使用传统银铝浆料的参考电池提高了0.41%.最后提出了LECO工艺诱导银-硅接触形成的物理模型,对二次高温烧结及二次LECO处理如何影响电池性能给出了合理的解释,这对于进一步理解和优化LECO工艺在TOPCon太阳电池中的应用具有重要意义.Laser induced sintering,also known as laser enhanced contact optimization(LECO),can significantly reduce the contact resistance between metal electrodes and silicon in TOPCon solar cells,thereby improving its efficiency.In this work,the effects of LECO process parameters such as reverse bias and laser intensity on the performance of TOPCon solar cells are investigated and their influencing mechanisms are analyzed in detail.In the LECO process,as the reverse bias voltage increases,the efficiency of the solar cell first increases and then decreases,while the contact resistivity first decreases and then increases.When the reverse bias voltage is high,the solar cell may experience reverse breakdown.Once the solar cell experiences reverse breakdown,both the illuminated and non-illuminated areas become conducting.Due to the current diversion effect,the local conducting current density in the illuminated area is much lower than the current density without reverse breakdown of the solar cell,Therefore,the Joule heating caused by this is also much smaller,and the contact resistance between the metal and silicon increases,resulting in a decrease in the efficiency of the solar cell.Secondly,the influence of secondary high-temperature sintering and secondary LECO on the performance of TOPCon is studied.When the secondary sintering temperature increases from 280℃to 680℃,the efficiency of TOPCon sharply decreases from 26.35%to 1.3%.However,by subjecting the solar cells that have undergone secondary high-temperature sintering to secondary LECO treatment,the efficiency can be restored to the level before the secondary high-temperature sintering.Thirdly,TOPCon solar cells prepared using improved pure silver paste does not form effective metal-semiconductor contact between the silver electrode and silicon before LECO treatment,resulting in an average efficiency of only 0.02%.However,after LECO treatment,the efficiency of solar cells using pure silver paste increases to 26.35%,which is 0.41%higher than the reference solar cells

关 键 词：激光诱导烧结 TOPCon 太阳电池 接触形成 二次高温烧结 

分 类 号：TM914.4[电气工程—电力电子与电力传动]