Thin Al2O3 passivated boron emitter of n-type bifacial c-Si solar cells with industrial process

We have presented thin Al2O3 (~4 nm) with SiNx:H capped (~75 nm) films to effectively passivate the boron-doped p+ emitter surfaces of the n-type bifacial c-Si solar cells with BBr3 diffusion emitter and phosphorus ion-implanted back surface field. The thin Al2O3 capped with SiNx:H structure not only possesses the excellent field effect and chemical passivation, but also establishes a simple cell structure fully compatible with the existing production lines and processes for the low-cost n-type bifacial c-Si solar cell industrialization. We have successfully achieved the large area (238.95 cm2) high efficiency of 20.89% (front) and 18.45% (rear) n-type bifacial c-Si solar cells by optimizing the peak sintering temperature and fine finger double printing technology. We have further shown that the conversion efficiency of the n-type bifacial c-Si solar cells can be improved to be over 21.3% by taking a reasonable high emitter sheet resistance. Copyright © 2017 John Wiley & Sons, Ltd.