掺(Ga, Si)银铝浆对n型TOPCon太阳能电池电性能的影响

Effect of Ga,Si doped silver aluminum paste on the electrical performance of n-type TOPCon solar cells

银铝浆是新一代太阳能电池(n型TOPCon)的关键材料,但其金属化后在Si发射极表面形成很大且很深的“银铝尖钉”,尖钉易击穿p-n结造成短路,成为限制其应用的瓶颈。引入Si、Ga元素对银铝浆进行优化,分别制备了掺Si和掺Ga,Si的银铝浆,研究其对金属化区域暗态饱和电流密度J0.metal、欧姆接触电阻Rc的影响机制。结果表明:掺入少量Si后,金属化区域未见明显“银铝尖钉”,说明掺Si后抑制了在浆料金属化时出现“银铝尖钉”的现象,对p-n结损伤较小,J0.metal下降,开路电压Voc上升,但是Rc增大。再掺入Ga组分后“银铝尖钉”明显变浅,数量变多,Rc下降,弥补了掺Si银铝浆欧姆接触差的弊端,有较高的电池转换效率;用扩散浓度测试仪(ECV)对发射极表层进行元素浓度分析,发现Ga分布于表层0~50 nm处,有利于改善欧姆接触。研究了Ga、Si的掺入量对银铝浆电性能的影响,电池转换效率最高达到24.68%,太阳能电池效率提升0.55%。

Silver aluminum paste is the key material of the new generation solar cell(n-type TOPCon),but after metallization,large and deep"silver aluminum spike"is formed on the surface of the Si emitter.The spike is easy to break through the p-n junction,causing short-circuit and constituting the bottleneck of application.In this study,Si and Ga elements were introduced to optimize the silver aluminum paste,and the silver aluminum paste doped with Si and Ga,Si were prepared respectively,and the mechanism of its influence on the dark state saturated current density Jo.meau and ohmic contact resistance Rin the metallization region was investigated.The results show that the doped Si inhibited the phenomenon of"silver aluminum spike"in the process of slurry metallization,The damage to p-n junction is small,with Jo.meal decreasing,Vo rising,but the R。increasing.,After re-dopingGacomponent,the"silver aluminumspikes"become significantly shallower,the number becomes more,and R。decreases,makingupfortheshortcomingsofSi doped ohmic contact,and the cell exhibiting a higher conversion efficiency.Using ECV to analyze the element concentration of emitter surface,it is found that Ga is distributed at O~50 nm of the surface layer,conducive to the improvement of ohmic contact.The influence of the amount of Ga and Si on the electrical properties of silver aluminum paste was explored,with the highest conversion efficiency of the cell reaching 24.68%and the efficiency of solar cells increasing by 0.55%.