氢等离子体处理钝化层对高效晶硅异质结太阳电池性能的影响

研究不同时间氢等离子体处理（HPT）氢化非晶硅a-Si:H（i）钝化层对高效晶硅异质结太阳电池（效率>23％）性能的影响。发现适当时间的HPT可改善钝化效果提升电池性能,但过长时间的HPT可导致薄膜钝化效果变差,有效少数载流子寿命降低。分析认为HPT时间过长,H原子进入到a-Si:H（i）薄膜层中,导致薄膜内部SiH₂增多,微结构因子（R）增大,薄膜质量变差。并且,适当时间的HPT改善太阳电池性能的幅度有限,而过长时间的HPT导致电池性能下降却很明显。因此,针对高效率的晶硅异质结太阳电池,应对钝化层沉积之后的HPT工艺进行谨慎控制。

EFFECT OF POST-DEPOSITION HYDROGEN PLASMA TREATMENT TO PASSIVATION LAYER ON PERFORMANCE OF SILICON HETEROJUNCTION SOLAR CELL

The effect of post-deposition hydrogen plasma treatment （HPT） to the intrinsic hydrogenated amorphous silicon （a-Si:H（i）） passivation layer on the performance of the silicon heterojunction （SHJ） solar cell with high efficiency （>23%） was investigated. It was found that HPT with an appropriate time could improve the passivation effect slightly and thus increase the solar cell efficiency. However, HPT with an over-long time obviously made the passivation effect deteriorate and the effective minority carrier lifetime （τeff） decrease. The analysis demonstrated that with the increase of HPT time, more and more hydrogen atoms entered the a-Si:H（i） layer, resulting in the SiH₂ amount increase in the layer. The microstructure factor （R） of the layer increased and the layer quality became poor. The results indicated that the HPT process should be controlled carefully when the original solar cell efficiency was high since the solar cell performance improvement from HPT was limited in such a case.