Article pubs.acs.org/JPCC
Stability of Lithiated Silicene from First Principles Tim H. Osborn* and Amir A. Farajian Department of Mechanical and Materials Engineering, Wright State University, Dayton, Ohio 45435, United States ABSTRACT: We explore the adsorption characteristics and stability of lithium on silicene from first principles. Our work shows that lithium adsorption could provide a unique method for isolating a stable silicene-based material while inducing a bandgap. We explore the energetics, temperature dependent dynamics, phonon frequencies, and electronic structure associated with lithium chemisorption on silicene. Our results predict the stability of completely lithiated silicene sheets (silicel) in which lithium atoms adsorb on the atom-down sites on both sides of the silicene sheet. Stability is confirmed by molecular dynamics simulations conducted at elevated temperatures and real phonon frequencies for all k-values. Upon complete lithiation, the band structure of silicene is transformed from a zero-gap semiconductor to a 0.368 eV bandgap semiconductor. This new, uniquely stable, two-atom-thick, semiconductor material could be of interest for nanoscale electronic devices.
I. INTRODUCTION Silicene,1−3 a promising new silicon analog of graphene, has recently been synthesized through epitaxial growth on silver substrates in the form of nanoribbons4,5 and nanosheets.6−9 Silicene has also been found to spontaneously segregate on a buffer layer of ZrB2 on the Si (111) surface.10 Although isolated silicene has not yet been reported, free-standing silicon nanosheets with a thickness
