Deformation-induced silicon nanostructures

Silicon (Si) has been widely used in advanced energy technologies including solar cells and secondary batteries because of its unique properties. However, up to now, the highest conversion efficiency of solar cells for silicon is just over 26%. Furthermore, during charge-discharge cycles, the Si voluminal expansion has been considered seriously, which greatly reduces the cycle life of the solar cell. Therefore, many research efforts have been focusing on the development of new phase, nanostructure, and pathways for improving the conversion efficiency and the cycle life of Si-based energy devices. In this review article, advanced methods, such as in situ transmission electron microscope nanomechanical testing, nanoscratching, nanoindentation, scratching at the nanoscale, and micrometer examination of the deformation-induced nanostructure of Si, are first presented. Subsequently, deformation-induced nanostructures in Si are proposed, in which the nanostructures are fabricated by a developed setup and novel diamond wheels. A new phase and a pathway in Si are manufactured and demonstrated by this setup. Finally, the perspectives and challenges of deformation-induced Si nanostructures for future developments are discussed. (C) 2020 Author(s).