Epitaxial growth of silicene on ultra-thin Ag(111) films

Abstract

Epitaxial growth of silicene on atomically flat ultra-thin Ag(111) films was investigated using scanning tunneling microscopy. The Ag films were prepared by low-temperature deposition of Ag on Si substrates, followed by soft annealing at room temperature. Patchy 4 × 4, √13 × √13, √7 × √7, and 2√3 × 2√3 silicene domains were nucleated on regions that were one monolayer lower than the pristine Ag surface after the initial morphological change had been completed. On the first-layer silicene containing the above domains, two types of √3 × √3 silicene domains (√3 × √3-α and β) were formed in the second layer. A bias voltage-independent Moiré pattern was observed for the √3 × √3-α silicene, and a bias voltage-dependent standing wave pattern for the √3 × √3-β silicene. The √3 × √3-β silicene had a dispersion relation that could be fitted using a linear function, although the resulting Fermi velocity was twice as large as the expected value. 2 New J. Phys. 16 (2014) 095004 J Sone et al New J. Phys. 16 (2014) 095004 J Sone et al

Interfacial Coupling and Electronic Structure of Two-Dimensional Silicon Grown on the Ag(111) Surface at High Temperature

“…However, more recent studies found that the surface reconstruction occurs on multilayered Si instead of a monolayer151617182930. In addition, such a phase resembles both geometrically and electronically the reconstructed Ag on Si(111), suggesting the formation of a surface alloy313233.…”

“…Thus far, freestanding silicene has not been synthesized. Most of the silicene structures were grown on Ag surfaces89101112131415161718, with a few successes on ZrB 2 19 and Ir20. Yet, interaction with the substrate may render it rather difficult to probe the intrinsic properties of silicene21222324.…”

Surfactant role of Ag atoms in the growth of Si layers on Si(111)√3×√3-Ag substrates

“…However, a recent experimental study suggested that the Ag(111) surface is not ideally stable and does not remain intact during silicene growth. 8 The Ag atoms readily exchange with Si atoms at the Ag(111) surfaces, making the growth process complicated and difficult to control.…”

“…One was equipped with a scanning tunneling microscope (STM) unit, 8 while the other was equipped with low energy electron diffraction (LEED) optics and a hemispherical electron energy analyzer for X-ray photoelectron spectroscopy (XPS) and angle-resolved photoelectron spectroscopy (ARPES). 19 Si(111) substrates were cleaned by flashing at 1470 K for 15 s and subsequent slow cooling to room temperature (RT).…”

Silicene on Other Two-dimensional Materials: Formation of Heterostructure

“…In addition, according to highly reactive surface, not only ultra-high vacuum system but also substrate for stabilizing sp 2 silicene should be necessary. In recent, there are many researches about fabrication of silicene on metal substrate, mainly Ag (Aufray et al, 2010;Gao & Zhao, 2012;Borensztein et al, 2014;Cahangirov et al, 2014;Chen & Weinert, 2014;Guo & Oshiyama, 2014;Johnson et al, 2014;Kawahara et al, 2014;Liu et al, 2014aLiu et al, , 2014bMahatha et al, 2014;Moras et al, 2014;Pflugradt et al, 2014a;Scalise et al, 2014;Shirai et al, 2014;Sone et al, 2014;Tchalala et al, 2014;Yuan et al, 2014). However the interaction between silicene and metal substrate degrades intrinsic properties of silicene.…”