非晶硅界面缓冲层对非晶硅锗电池性能的影响

摘要

In the light of the open circuit voltage and fill factor reduction resulting from band gap discontinuities and high defect densities at interfaces when more germanium is mixed into the intrinsic layer of hydrogenated amorphous silicon germanium solar cell, the insertion of a-Si:H buffer layer with proper band gap into PI interface not only mitigates band gap discontinuities and interface recombination, but also improves the electric field distribution by reducing the defect densities at PI interface, thus the collection efficiency of a-SiGe:H solar cell is enhanced. By inserting a-Si:H buffer layer into IN interface and designing band gap profile along the a-SiGe:H intrinsic layer further, the 8.72%conversion efficiency of single junction a-SiGe:H solar cell is achieved when only Al back reflector is added as back contact.%针对非晶硅锗电池本征层高锗含量时界面带隙失配以及高界面缺陷密度造成电池开路电压和填充因子下降的问题，通过在PI界面插入具有合适带隙的非晶硅缓冲层，不仅有效缓和了带隙失配，降低界面复合，同时也通过降低界面缺陷密度改善内建电场分布，从而提高了电池的收集效率.进一步引入IN界面缓冲层以及对非晶硅锗本征层进行能带梯度设计，在仅采用Al背电极时，单结非晶硅锗电池转换效率达8.72%.