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

Abstract

AbstractWe 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.