FisMat2017 - Submission - View

Abstract's title: Li-intercalated Graphene on SiC(0001): an STM study
Submitting author: Stefan Heun
Affiliation: NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore
Affiliation Address: Piazza San Silvestro 12, 56127 Pisa
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Sara Fiori (NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy), Yuya Murata (NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy), Stefano Veronesi (NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy), Antonio Rossi (NEST, Scuola Normale Superiore and Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy), Camilla Coletti (Center for Nanotechnology Innovation @NEST, Istituto Italiano di Tecnologia, Piazza San Silvestro 12, 56127 Pisa, Italy)
Abstract

We present a systematical study via scanning tunneling microscopy (STM) and low-energy electron diff raction (LEED) on the eff ect of the exposure of Lithium (Li) on graphene on silicon carbide (SiC). We have investigated Li deposition both on epitaxial monolayer graphene and on bu ffer layer surfaces on the Si-face of SiC. At room temperature, Li immediately intercalates at the interface between the SiC substrate and the bu ffer layer and transforms the buff er layer into a quasi-free-standing graphene. This conclusion is substantiated by LEED and STM evidence. We show that intercalation occurs through the SiC step sites or graphene defects. We obtain a good quantitative agreement between the number of Li atoms deposited and the number of available Si bonds at the surface of the SiC crystal. Through STM analysis, we are able to determine the interlayer distance induced by Li-intercalation at the interface between the SiC substrate and the buff er layer.