The project is jointly funded by the Electronic and Photonic Materials (EPM) and the Solid State and Materials Chemistry (SSMC) Programs, both in the Division of Materials Research (DMR).
Non-technical Description: The exotic physical phenomena discovered in graphene have spurred great scientific interest in various two-dimensional (2D) materials. 2D materials with only one or a few atomic layers in thickness are favorable over bulk materials in terms of device scalability and the extension of Moore's law. This project focuses on the exploration and band structure tuning of silicene, a monolayer of Si atoms arranged in a honeycomb pattern, which has the potential to be adapted to the mainstream silicon-based electronics and applications in spintronics. The educational component includes training graduate students in an interdisciplinary academic environment, integrating research with undergraduate education and with the Research Experience for Undergraduates program at Michigan State University, recruiting minority students, and disseminating research to an even broader audience through outreach activities such as Science Theatre that has been established at the University.
Silicene is an emerging 2D material with the promise of exhibiting Dirac physics like graphene but of a larger spin-orbit coupling. To date most of the silicene growth has been carried out on Ag(111) substrate, with marginal success on zirconium diboride and iridium. However, the strong interaction with the substrate renders it difficult to isolate silicene and to measure its electrical transport properties. This project aims to address these critical issues by 1) exploring growth of silicene on insulating substrates such as boron nitride in order to probe its intrinsic properties; and 2) tuning the band gap and carrier concentration of silicene via surface chemical functionalization. A wide and continuous tuning of the band structure is important for exploring properties of silicene and its potential applications in switching devices. A comprehensive experimental approach including scanning tunneling microscopy/spectroscopy, non-contact atomic force microscopy, ultraviolet and x-ray photoelectron spectroscopy is taken to characterize the surface and to measure the electronic structures of silicene.
