Silicon heterojunction solar cells with up to 26.81% efficiency achieved by electrically optimized nanocrystalline-silicon hole contact layers
Hao Lin, Miao Yang, Xiaoning Ru, Genshun Wang, Shi Yin, Fuguo Peng, Chengjian Hong, Minghao Qu, Junxiong Lu, Liang Fang, Can Han, Paul Prócel, Olindo Isabella, Pingqi Gao, Zhenguo Li, Xixiang Xu
Abstract
Abstract Silicon heterojunction (SHJ) solar cells have reached high power conversion efficiency owing to their effective passivating contact structures. Improvements in the optoelectronic properties of these contacts can enable higher device efficiency, thus further consolidating the commercial potential of SHJ technology. Here we increase the efficiency of back junction SHJ solar cells with improved back contacts consisting of p-type doped nanocrystalline silicon and a transparent conductive oxide with a low sheet resistance. The electrical properties of the hole-selective contact are analysed and compared with a p-type doped amorphous silicon contact. We demonstrate improvement in the charge carrier transport and a low contact resistivity (<5 mΩ cm 2 ). Eventually, we report a series of certified power conversion efficiencies of up to 26.81% and fill factors up to 86.59% on industry-grade silicon wafers (274 cm 2 , M6 size).