ABSTRACT

During the last two decades, a variety of core–shell structures involving nano-Si as one of the components have been synthesized and investigated. Such structures are important both from the standpoint of understanding basic physics and chemistry as well as for diverse applications. Attempts to understand the controversial luminescence photophysics of ultra-small Si nanocrystals (NCs) have been primarily based on investigation of these NCs capped with a variety of materials, thereby forming core–shell nanostructures of some sort (English et al. 2002; Dasog et al. 2013; Wang et al. 2015; Wen et al. 2015). On the other hand, applications of Si nanostructures either as Li-ion battery anodes (Hwang et al. 2012a; Wu et al. 2013) or as active material of solar cells (Tang et al. 2011; Adachi et al. 2013) involve coating nano-Si with appropriate materials. The importance of such core–shell materials can therefore be hardly overemphasized. In this article, we will try to deal with the preparation, properties and applications of the major variants of Si-based core–shell nanostructures with an emphasis on understanding the interface of the core and the shell.