Unraveling the Highly Complex Nature of Antimony on Pt(111)

Abstract

partially driven to complement and fulfill the absence of electronic band gap in graphene, [5] as this property is technologically relevant in some applications. In this sense, the synthesis of a large number of 2D materials from group IV and V elements like silicene, [6,7] germanene, [8,9] or antimonene [10,11] has been reported in the literature. In particular, metallic substrates have been commonly adopted as the growing support for these novel materials, providing a platform to explore their properties. However, several issues have recently been raised by different authors regarding the successful synthesis of pure layers of these bidimensional materials, especially when they are grown on metal substrates. [12][13][14][15][16][17][18][19] Therefore, further research is necessary to throw light on this present controversy.Among this vast portfolio of 2D materials, antimonene has received a strong amount of interest due to its attractive properties. It has been theoretically predicted to feature a tunable semiconducting band gap, [20,21] a relatively high carrier mobility [22] or quantum spin Hall effect. [23] Experimentally, different methods have been employed to synthesize antimonene. From top-down approaches, few-layer antimonene crystals can be obtained through liquid-phase [24] or mechanical [25] exfoliation. In the latter, thickness down to monolayer can be isolated. [25] Bottomup synthesis also constitutes a versatile method. In particular, the growth of antimonene sheets have been reported by depositing Sb on metal chalcogenides, [26,27] semiconductors, [28] and metal [10,11] substrates. Nevertheless, other studies on the growth and adsorption of Sb on metallic substrates suggest a different nature of Sb atoms. According to these studies, on gold, copper, and silver single-crystal, the experimental results are best explained as a substitutional surface alloy presenting a stacking fault with respect to the underlying metal support. [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43] Such substitutional adsorption of Sb was also theoretically found to be the most energetically favored for Sb compared to on surface sites. [37,[44][45][46] In this article, the growth of Sb on single-crystal Pt(111) has systematically been investigated via a combination of scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and Auger electron spectroscopy (AES) techniques under ultra-high vacuum (UHV) conditions. Pt(111) has been chosen as the substrate since it differs from the coinage metals (Cu, Ag and Au) that have been used in mainly all the studies performed until now. Therefore, understanding the behavior of Understanding the growth behavior of group-V elements on metal surfaces provides valuable information that can shed light on the feasibility of tailoring atomically thin monoelemental 2D polymorphs composed of pnictogens on these metallic substrates. Here, by combining scanning tunneling microscopy (STM), low energy electron diffraction and Auger electron spectroscopy measurements...

Peculiar Structural Phase of a Single-Atom-Thick Layer of Antimony

“…The crystallographic structure of the Sb layer does not resemble any known stable antimonene structures (α and β phases) or those theoretically predicted and presumed to be unstable . It is also different from the Sb structures obtained on other surfaces. − ,, In order to shed more light on the obtained complicated crystallographic structure of the Sb layer, DFT model calculations have been performed. Very good agreement between the DFT results and the STM measurements has been obtained for 15 Sb atoms per 1· a W [001] × 21· a W [11̅0] unit cell.…”

“…1 It is also different from the Sb structures obtained on other surfaces. [8][9][10][11]15,16 In order to shed more light on the obtained complicated crystallographic structure of the Sb layer, DFT model calculations have been performed. Very good A more detailed inspection of the atomic structure reveals smaller building blocks of the unit cell, as marked by the red dashed lines in Figure 4a.…”

“… 1 It is also different from the Sb structures obtained on other surfaces. 8 − 11 , 15 , 16 In order to shed more light on the obtained complicated crystallographic structure of the Sb layer, DFT model calculations have been performed. Very good agreement between the DFT results and the STM measurements has been obtained for 15 Sb atoms per 1· a W [001] × 21· a W [11̅0] unit cell.…”

Tracing the structural evolution of quasi-freestanding germanene on Ag(111)

“…The large number of recently published controversial studies and results on what phases are formed and what they are called do not proceed the understanding of the structural formation process of germanene on Ag(111). Above all, the critical discussion of controversial structural models proposed, as also known from other materials, is highly topical and contemporary for the progress in the field of 2D materials 37 – 40 .…”

Metal-phosphorus network on Pt(111)

“…Platinum (Pt) is a catalytic material with excellent physical and chemical properties and is a common substrate for epitaxial growth of 2D materials [35][36][37][38]. In this paper, we report the observation of platinum-phosphorus network (PtPhoN) superstructures grown by MBE of P on Pt(111).…”