APS March Meeting 2014
Volume 59, Number 1
Monday–Friday, March 3–7, 2014;
Denver, Colorado
Session T51: Focus Session: Beyond Graphene: Synthesis, Defects, Structure, and Properties VIII
11:15 AM–2:15 PM,
Thursday, March 6, 2014
Room: Mile High Ballroom 1E
Sponsoring
Unit:
DMP
Chair: Valentino Cooper, Oak Ridge National Laboratory
Abstract ID: BAPS.2014.MAR.T51.1
Abstract: T51.00001 : Physical foundations and future perspectives of the epitaxial silicene
11:15 AM–11:51 AM
Preview Abstract
Abstract
Author:
Alessandro Molle
(CNR-IMM, Laboratorio MDM)
Silicene, a graphene-like Si monolayer, has been so far a fascinating
theoretical hypothesis [1] with no experimental counterpart as due to the
natural sp$^{3}$ hybridization of Si bonding. Artificially forcing
the silicene lattice was firstly made possible in the epitaxial growth of a
Si monolayer on Ag(111) substrates [2]. Here it is shown through an \textit{in situ}
scanning tunnelling microscopy investigation [3] that unlike graphene,
non-trivial atomistic arrangements (reconstructions) can coexist in
multiphase silicene nanosheets as due to the balance between planar and
buckled bonding [1]. This structural complexity is kinetic in character as
it can be governed by tuning the thermal condition during growth or in a
post-growth stage, and it is expected to bring absolutely peculiar physical
properties [4].
Silicene is intrinsically limited by its intimate chemical instability. An
\textit{ad hoc} engineered Al$_{2}$O$_{3}$ encapsulation is proposed for
\textit{ex situ} investigations such as Raman spectroscopy [5]. Supported by \textit{ab initio} calculations,
the measured Raman spectrum of the silicene phases is consistent with a
prevailing a sp$^{2}$ hybridization, and it also evidences a
reconstruction dependent resonant/non-resonant behavior [6].
To integrate silicene in transistor structures, decoupling from the metallic
templates is highly desired. New directions in this respect are outlined
which include silicene deposition on cleavable substrates (e.g. Ag(111)
films on mica), and the van der Waals growth of Si nanosheets on layered
templates (such as MoS$_{2}$ layers). Perspectives on the silicene
``portability'' for a device-oriented exploitation will be discussed.
\\[4pt]
[1] S. Cahangirov, et al., Phys. Rev. Lett. 102, 236804 (2009).\\[0pt]
[2] P. Vogt, et al., Phys. Rev. Lett. 108, 155501 (2012).\\[0pt]
[3] D. Chiappe, et al., Adv. Mater. 24, 37, 5088 (2012).\\[0pt]
[4] M. Ezawa, Phys. Rev. Lett. 109, 055502 (2012).\\[0pt]
[5] A. Molle, et al., Adv. Func. Mat. 23, 4340 (2013).\\[0pt]
[6] E. Cinquanta, et al. J. Phys. Chem. C 117, 16719 (2013).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2014.MAR.T51.1