PERC电池制程详解
2019-08-17 12:36
原理:一定浓度、一定温度条件下,碱溶液与硅片反应,各向异性腐蚀;
Principle:Etching silicon in anisotropic KOH solution;
目的:去除表面损伤层,降低表面反射率;
Purpose:Saw damage remove and reduce surface reflection;
化学反应式(chemical equation):Si + 2KOH + H2O → K2SiO3 + 2H2↑
绒面结构(Surface structure)




原理:采用三氯氧磷(POCl3)液态源扩散方法,在硅片表面形成N型层;
Principle:POCl3 liquid diffusion, forming N type Si on surface;
目的:形成PN结(太阳电池核心单元);
Purpose: Forming PN junction;
化学反应式(chemical equation) :5POCl3→3PCl5+P2O5(High T)2P2O5+5Si→5SiO2+4P↓




原理:采用激光,在硅片表面形成局域重掺杂N型层;
Principle:Use laser to form heavy N type Si (local) on surface;
目的:形成局域重掺杂N型层;
Purpose: Forming heavy N type Si (local) on surface;




原理:实现硅片的单面腐蚀;
Principle: Single side etch of silicon wafer;
目的:PN结边缘隔离和背面抛光;
Purpose: Isolation of PN junction and polishing.
化学反应式(chemical equation) :Si+4HNO3 → SiO2+4NO2↑+2H2O SiO2+4HF → SiF4↑+2H2O SiF4+2HF → H2SiF6




原理:在表面生长SiO2钝化膜;
Principle:Grow SiO2 film on surface;
目的:提升开路电压,提升效率。
Purpose: Increase Voc, improve efficiency.
化学反应式(chemical equation) :
Si+O2 → SiO2




原理:PECVD沉积AlOx+SiNx薄膜;
Principle: PECVD deposition of AlOx+SiNx thin film;
目的:制备背面钝化介质层;
Purpose: Rear side AlOx/SiNx dielectric layer.
工艺流程(process flow):




PECVD/ARC原理:PECVD沉积SiNx减反射膜;
Principle: PECVD deposition of Anti-reflective coating;
目的:表面钝化和降低反射率;
Purpose: Surface passivation and reduce reflection.




原理:激光消融背面介质层;
Principle: Laser ablation of dielectric layer;
目的:形成局域背场接触,收集电流;
Purpose:Forming local BSF(back surface filed) to collect current.




丝网印刷&烧结(Screen printing& Co-firing):
PERC电池需使用专用银铝浆料,使电池性能达到最优。
PERC cell use special Ag&Al paste,for optimum of cell performance.




原理:
Principle:


目的:降低光衰减;
Purpose:Decrease LID.
