Spatial analysis of interactions at the silicene/Ag interface: first principles study

Stephan, Régis; Hanf, Marie-Christine; Sonnet, Philippe

doi:10.1088/0953-8984/27/1/015002

Cited by 29 publications

(32 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…As such, the resulting electronic structure is not desirable for 2D electronic applications. This result has now been reproduced through a number of theoretical and experimental techniques, including density functional theory (DFT) calculations, angle‐resolved photoemission spectroscopy (ARPES), scanning tunneling spectroscopy (STS), and soft X‐ray emission and absorption spectroscopies (XES and XAS, respectively). Epitaxial silicene ML research now primarily focuses on functionalization of the ML in order to weaken its interaction with the Ag(111), or ML silicene deposition on alternative, typically nonmetallic substrates.…”

Section: Introductionmentioning

confidence: 87%

Stability and Electronic Characteristics of Epitaxial Silicene Multilayers on Ag(111)

Johnson

Muir

Kurmaev

et al. 2015

Adv Funct Materials

View full text Add to dashboard Cite

4083wileyonlinelibrary.com of spin-orbit coupling. [ 5 ] This suggests that if stable freestanding silicene were to be realized, it should be a candidate for many of the same applications for which graphene is currently being considered. In fact, silicene may even have some advantages over its carbon-based counterpart. Its inherent buckling could allow for bandgap control, [ 6 ] spin polarization control, [ 7 ] and an ambipolar fi eld effect [ 3 ] all through the application of a gating voltage on an undoped freestanding silicene sheet. In addition, the transition to 2D electronics design and manufacturing should be much smoother if it remains based around the same element (silicon) as current 3D processes.On the experimental side, honeycomb monolayer (ML) lattices of Si atoms have been observed on the Ag(111) face, [8][9][10][11][12][13] the Ir(111) face, [ 14 ] MoS 2 , [ 15 ] and the ZrB 2 (0001) face. [ 16 ] Further, stable MLs have been theoretically predicted on SiC(0001) [ 17 ] and h-BN. [ 17,18 ] However, the degree to which these epitaxial MLs actually represent freestanding silicene has been called into question. The most thoroughly studied epitaxial silicene samples are those deposited on Ag(111), which were fi rst observed in 2012 when Vogt et al. [ 8 ] reported a (3 × 3) silicene supercell commensurate with the (4 × 4) Ag(111) supercell (hereafter referred to as the (3 × 3)/ (4 × 4) ML). Since then, a number of rotated (√7 × √7)R19.1° silicene MLs have been identifi ed on the (√13 × √13)R13.9° Ag(111) supercell [9][10][11][12]19 ] (hereafter the (√7 × √7)/(√13 × √13) ML), and an unstable and highly defective (√7 × √7) silicene reconstruction on the (2√3 × 2√3)R30° Ag(111) cell. [ 20 ] Initially, it was thought that the prototypical (3 × 3)/(4 × 4) ML bore the hallmarks of a Dirac cone in its electronic structure. [ 8 ] However, it has now been shown that these ML confi gurations result in a metallic Si sheet interacting signifi cantly with the underlying Ag substrate. As such, the resulting electronic structure is not desirable for 2D electronic applications. This result has now been reproduced through a number of theoretical and experimental techniques, including density functional theory (DFT) calculations, [ 13,[21][22][23] angle-resolved photoemission spectroscopy (ARPES), [ 22 ] scanning tunneling spectroscopy [ 24 ] (STS), and soft X-ray emission and absorption spectroscopies [ 13 ] (XES and XAS, respectively). Epitaxial silicene ML research now primarily focuses on functionalization of the ML in order to weaken its interaction with the Ag(111), or ML silicene deposition on alternative, typically nonmetallic substrates.Recently, a major development in silicene research occurred when the fi rst silicene-based transistor was manufactured and In this study, the stability and electronic characteristics of epitaxial silicene bilayers and multilayers on the Ag(111) surface are investigated through synchrotron-based soft X-ray emission and absorption spectroscopy and fi rstprinciples, full-potential de...

show abstract

Section: Introductionmentioning

confidence: 87%

Stability and Electronic Characteristics of Epitaxial Silicene Multilayers on Ag(111)

Johnson

Muir

Kurmaev

et al. 2015

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

“…Now, for the Si(111) surface, the dangling bond is occupied by an electron. In contrast, in silicene/Ag(111), there is a charge transfer from the top Si atoms to the Ag substrate, with the result that these Si atoms carry in a positive charge 27 . One could expect a charge reorganization implying a possible modification of this charge transfer upon benzene adsorption; however our calculations show that the latter is only weakly influenced by the presence of the C 6 H 6 molecule.…”

Section: Resultsmentioning

confidence: 99%

“…The optB86b-vdW is a van der Waals density functional which takes into account the long range interactions 45,46 , while in the DFT-D2 method the semi -empirical energetic correction of Grimme is added to the total energetic calculations [47][48][49] . The Brillouin zone is sampled by means of (3 × 3 × 1) k−points, as done in previous works 17,27,50 . A plane-wave energy cutoff of 400 eV has been taken.…”

Section: Calculation Detailsmentioning

confidence: 99%

“…For (3 × 3) silicene/(4 × 4) Ag(111), one in three Si atoms lies at a higher position than the others; thus pure sp 3 and sp 2 -sp 3 bonds are formed 17 . It appears that the silicene/Ag interface plays a major role, with the presence of localized charges between the bottom Si plane and the Ag surface 27 . Moreover, electrical charge is transferred from the top Si atoms to the Ag substrate as well as to the other Si atoms.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular functionalization of silicene/Ag(111) by covalent bonds: a DFT study

Stephan

Hanf

Sonnet

2015

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Among the 2D crystals, silicene, which forms sp(2)-sp(3) bonds, is expected to present a higher reactivity than graphene, characterized by sp(2) bonds only. However, silicene functionalization, in particular with organic molecules, remains an open question. By means of density functional theory, we study the adsorption of benzene, a model organic molecule, on (3 × 3) silicene on the (4 × 4) Ag(111) surface. Our calculations show that the dispersion interactions must be taken into account in order to describe this system properly. The adsorption energy is calculated by means of the semi-empirical dispersion-corrected density functional theory (DFT-D2) and the optB86b-vdW density functional. The charge density and electron localization function maps indicate that the molecule is chemisorbed on the silicene surface by means of two Si-C covalent bonds. In agreement with charge density difference calculations, two C-C double bonds are formed in the benzene molecule, which adopts a butterfly configuration. The silicene lattice is slightly deformed upon benzene adsorption, but the Si-Si distance remains the same as in bare silicene/Ag(111). Bader analysis shows a charge transfer from top Si atoms to both molecules and Ag substrates. Finally, we show that the covalent functionalization of silicene is possible.

show abstract

“…Silicene is a structure with a hexagonal lattice which forms when a single layer of silicon atoms is deposited, for example, on a Ag substrate. [31][32][33][34][35][36][37][38][39][40][41][42][43][44] The discovery of this new material in 2010 has led silicene to be considered as a promising novel material for nanoelectronics. 31 Silicene should naturally benefit from current Si-based research and development technology.…”

Section: Introductionmentioning

confidence: 99%

Opening the way to molecular cycloaddition of large molecules on supported silicene

Stephan

Hanf

Sonnet

2015

The Journal of Chemical Physics

Self Cite

View full text Add to dashboard Cite

Within density functional theory, the adsorption of the H2Pc molecule on the (3 × 3) silicene/(4 × 4) Ag(111) surface has been investigated. We observe an electronic redistribution in the central macrocycle of the H2Pc molecule and the formation of two Si - N covalent bonds between the molecule and the silicene, in agreement with a cycloaddition reaction. However, while on SiC(0001)(3 × 3) or Si(111)(√3×√3)R30°-boron, the H2Pc molecule remains planar, and the H2Pc molecule takes a butterfly conformation on the silicene/Ag substrate due to an electrostatic or a polarization repulsion between the molecule and the silicene. Our study opens a way to the experimental adsorption of large organic molecules on supported silicene.

show abstract

Spatial analysis of interactions at the silicene/Ag interface: first principles study

Cited by 29 publications

References 45 publications

Stability and Electronic Characteristics of Epitaxial Silicene Multilayers on Ag(111)

Stability and Electronic Characteristics of Epitaxial Silicene Multilayers on Ag(111)

Molecular functionalization of silicene/Ag(111) by covalent bonds: a DFT study

Opening the way to molecular cycloaddition of large molecules on supported silicene

Contact Info

Product

Resources

About