Interfacial Engineering of Cu2O Passivating Contact for Efficient Crystalline Silicon Solar Cells with an Al2O3 Passivation Layer

• DOI: 10.1021/acsami.1c08258
• Publication Date: 2021-06-14T07:10:54Z
• Authors: Le Li; Guanlin Du; Xi Zhou; Yinyue Lin; Yuanwei Jiang; Xingyu Gao; Linfeng Lu; Gang Li; Wei Zhang; Qiang Feng; Jilei Wang; Liyou Yang; Dongdong Li
• Keywords: 0103 physical sciences; 02 engineering and technology; 0210 nano-technology; 7. Clean energy; 01 natural sciences; 0104 chemical sciences

Passivating contacts that simultaneously promote carrier selectivity and suppress surface recombination are considered as a promising trend in the crystalline silicon (c-Si) photovoltaic industry. In this work, efficient p-type c-Si (p-Si) solar cells with cuprous oxide (Cu2O) hole-selective contacts are demonstrated. The direct p-Si/Cu2O contact leads to a substoichiometric SiOx interlayer and diffusion of Cu into the silicon substrate, which would generate a deep-level impurity behaving as carrier recombination centers. An Al2O3 layer is subsequently employed at the p-Si/Cu2O interface, which not only serves as a passivating and tunneling layer but also suppresses the redox reaction and Cu diffusion at the Si/Cu2O interface. In conjunction with the high work function of Au and the superior optical property of Ag, a power conversion efficiency up to 19.71% is achieved with a p-Si/Al2O3/Cu2O/Au/Ag rear contact. This work provides a strategy for reducing interfacial defects and lowering energy barrier height in passivating contact solar cells.