Engineering Heterointerface for High-efficiency Silicon Solar Cells

High-performance passivating contacts are crucial to realizing high-efficiency crystalline silicon (c-Si) solar cells. The passivating contacts can efficiently transport photogenerated carriers from c-Si to metal electrodes. A representative passivating contact is the stack of ultra-thin silicon oxide (SiOx) and doped polycrystalline Si. In the structure, the layer thickness of silicon oxide is limited to 1～2 nm to collect photogenerated carriers. For further improvements, we have developed NAnocrystal Transport path in Ultra-thin dielectrics for REinforced passivating contact（NATURE contact）as a new passivating contact. The NATURE contact consists of Si nanocrystals (NCs) and SiOx matrix. The Si NCs and the SiOx matrix function as carrier transport paths and passivation layers for the c-Si surface, respectively. The NATURE contact can attain good passivation performance and conductive property. In this paper, we briefly explain the fundamentals of the passivating contacts and introduce the properties of the NATURE contact.