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This study employs density functional theory calculations to analyze the structural and mechanical properties of stanene nanosheets (SnNs), including elastic moduli, Poisson's ratio, and plastic behavior under various loads. Parameters of the Morse potential function governing stanene atom interactions are explored. The nanosheets demonstrate isotropic behavior with minimal discrepancy in Young's modulus between armchair and zigzag directions. Additionally, a progressive finite element method investigates fracture mechanics, simulating the mechanical response using a modified Morse potential function. The nonlinear stress–strain relationships for both pristine and defective armchair and zigzag stanene nanosheets are elucidated, revealing brittle behavior and slightly higher mechanical properties in armchair stanene. Single-vacancy defects significantly impact mechanical properties of stanene, while Stone–Wales defects have negligible effects. [ABSTRACT FROM AUTHOR]

As well-known electrocatalysts with good catalytic efficiency for carbon dioxide reduction reaction (CO2RR) towards the production of formate, tin (Sn)-based catalysts have aroused broad concern. Here, free-standing porous stanene is synthesized for the first time by a facile wet chemical method, and its excellent electrocatalytic performance for formate (HCOO-) formation in CO2RR is demonstrated. High Faradaic efficiency (F.E., 93% at -930 mV versus reversible hydrogen electrode (RHE)) can be achieved in the CO2RR catalyzed by stanene in 0.5 m KHCO3 aqueous solution. The in situ Mössbauer spectra reveal that zero-valent Sn aids in improving the selectivity of formate production. Furthermore, density functional theory calculations suggest that the high selectivity of HCOO- of CO2RR on stanene mainly originates from the edge sites on Sn (100). To further explore the practicability of the stanene-based catalysts for CO2RR, stanene decorated by 3 wt% BP-2000 is prepared, showing an excellent F.E. of 98% at -930 mV versus RHE due to the higher exposure of catalytic active sites. These new findings of the activity origination and reaction mechanism of stanene contribute to the deeper understanding of Sn-based catalysts for CO2RR, which is beneficial for the future designation of highly efficient CO2RR catalysts. [ABSTRACT FROM AUTHOR]

Two-dimensional stanene is limited in its application in nanoscale optoelectronic devices due to its zero-bandgap. Based on first-principles calculations of density functional theory, the effects of adsorption of Be atoms with different coverages and torsional deformation on the structure, electricity, and optics of stanene are systematically investigated. The adsorption of Be atoms makes stanene have an adjustable bandgap, the surface state is successfully transformed from a zero-bandgap quasi-metal to a semiconductor with a maximum bandgap of 0.260 eV, the change in Be atom coverage causes a blueshift of the absorption and reflection peaks. Torsional deformation can effectively adjust the bandgap of stanene, which varies from 0.278 eV to 0.110 eV. Torsion enhances the maximum absorption peak of light. Stanene is expected to be a candidate material for designing new nanoelectronic devices. [ABSTRACT FROM AUTHOR]

In this study, the adsorption of the most common hazardous gases (CO, NO, NO2, and CO2) on the stanene armchair nanoribbon of width 6 (H‐ASnNR(6)) is investigated using density functional theory. The most stable adsorption sites, adsorption energies, charge transfer, electronic features, transmission spectra, and current–voltage analysis are explored. All molecules are physisorbed on H‐ASnNR(6) through van der Waals interactions, indicating a potential use for this material in recoverable gas sensors, and all gas molecules act as acceptors. Additionally, the highest and the lowest charge transfer is related to the NO and CO2 molecules, respectively. It is revealed that the adsorption of NO and NO2 affects the electronic properties of the H‐ASnNR(6), and the system displays conducting behavior, while the influence of CO and CO2 gas molecules on the electrical properties of H‐ASnNR(6) is relatively small. The results demonstrate that compared to pristine H‐ASnNR(6), the transmission function of the gas plus H‐ASnNR(6) system undergoes a significant change, particularly after the adsorption of NO and NO2 molecules. The presence and absence of the molecules are shown by current–voltage (I–V) characteristic results. The results suggest that H‐ASnNR(6) has the potential to be used in gas molecule detection applications. [ABSTRACT FROM AUTHOR]

Two-dimensional materials have benefited scientists and technologists in many ways over the past two decades. Stanene is one of the most recent members of the 2D family, with a stronger spin–orbit coupling than graphene, which has led to predictions of several interesting properties. However, in spite of extensive theoretical investigations over the past few years, experimental realization has been limited to growth by either the molecular beam epitaxy or liquid-phase exfoliation using laser ablation. On the application front, capabilities related to Li-ion batteries and gas sensors have been modeled using first-principles DFT calculations. In this short review, we present the current state of the art in terms of both experimental and theoretical efforts related to stanene and possible future directions. [ABSTRACT FROM AUTHOR]

Stanene, composed of tin atoms, is a member of 2D-Xenes, two-dimensional single element materials. The properties of the stanene can be changed and improved by applying deformation, and it is important to know the range of in-plane deformation that the stanene can withstand. Using the Tersoff interatomic potential for calculation of phonon frequencies, the range of stability of planar stanene under uniform in-plane deformation is analyzed and compared with the known data for graphene. Unlike atomically flat graphene, stanene has a certain thickness (buckling height). It is shown that as the tensile strain increases, the thickness of the buckled stanene decreases, and when a certain tensile strain is reached, the stanene becomes absolutely flat, like graphene. Postcritical behaviour of stanene depends on the type of applied strain: critical tensile strain leads to breaking of interatomic bonds and critical in-plane compressive strain leads to rippling of stanene. It is demonstrated that application of shear strain reduces the range of stability of stanene. The existence of two energetically equivalent states of stanene is shown, and consequently, the possibility of the formation of domains separated by domain walls in the stanene is predicted. [ABSTRACT FROM AUTHOR]

Stanene (Sn)-based materials, with a graphene-like hexagonal structure, are now attracting considerable interest for potential applications in photoelectricity. However, the nonlinear optical properties of stanene remain largely unexplored. In this work, we prepared different sizes of stanene by liquid phase exfoliation and differential centrifugation methods, including two-dimensional (2D) Sn nanosheets (NSs) and zero-dimensional (0D) Sn nanodots (NDs). Z-scan measurements reveal that 2D Sn NSs exhibited high saturable absorption behavior, while the 0D Sn NDs led to reverse saturable absorption. Femtosecond ultrafast transient absorption spectra revealed that the reverse saturable absorption of Sn NDs is derived from a stronger excited state absorption and faster exciton relaxation dynamics. This research expands the potential applications of stanene in laser shielding and other ultrafast photonics technologies.

Group IV graphene analogues such as stanene, plumbene, etc. have drawn attention because of their large spin–orbit coupling and thus being promising candidates for topological insulator. However, fabrication of these ultrathin monolayers is a daunting task. To reduce the difficulties of the fabrication of 2D topological insulators, bilayer materials with sizable nontrivial bandgaps can be a viable option. Chemically decorated bilayer stanene is a novel structure which has not been studied before. Herein, the topological characteristics of halogen‐decorated bilayer of stanene are studied and their topological nontriviality is confirmed by calculating the Z2 invariant. As the topological nontriviality can be preserved for these bilayers, these materials will have advantages over their monolayer counterparts in terms of fabrication difficulties. Halogen‐decorated stanene bilayers (except Br) are topologically nontrivial and their nontrivial nature is tunable by external strain. Hybrid functional (HSE06) has been employed to calculate the band structures of the materials at various strains. Also, the band structures of their zigzag nanoribbons have been analyzed. Lastly, the formation energy, quantum molecular dynamics, and phonon dispersion confirm their electronic and structural stability. The proposed material may speed up the fabrication of 2D topological insulators aiming future spintronic and high‐speed electronic devices. [ABSTRACT FROM AUTHOR]

Today, two-dimensional materials are one of the key research topics for scientists around the world. Interest in 2D materials is not surprising because, thanks to their remarkable mechanical, thermal, electrical, magnetic, and optical properties, they promise to revolutionize electronics. The unique properties of graphene-like 2D materials give them the potential to create completely new types of devices for functional electronics, nanophotonics, and quantum technologies. This paper considers epitaxially grown two-dimensional allotropic modifications of single elements: graphene (C) and its analogs (transgraphenes) borophene (B), aluminene (Al), gallenene (Ga), indiene (In), thallene (Tl), silicene (Si), germanene (Ge), stanene (Sn), plumbene (Pb), phosphorene (P), arsenene (As), antimonene (Sb), bismuthene (Bi), selenene (Se), and tellurene (Te). The emphasis is put on their structural parameters and technological modes in the method of molecular beam epitaxy, which ensure the production of high-quality defect-free single-element two-dimensional structures of a large area for promising device applications. [ABSTRACT FROM AUTHOR]

Stanene is a quantum spin hall insulator and a favourable material for electronic and optoelectronic devices. Density functional theory (DFT) calculations are performed to study the band gap opening in stanene by investigating the effect of beryllium and magnesium doped stanene single layer to study the electronic and structural properties in stanene. The electronic band energy of pure stanene without spin orbit coupling (SOC) appear to show no energy gap at the Fermi level showing that stanene is a gapless material with Dirac cones at the K point and the band gap opens by a gap of 0.08 eV is opened at the K point. The electronic structure of Be and Mg doped stanene shows that the Fermi level is shifted towards the valance band edge when compared to pure stanene. We have considered 6.25, 12.5, 18.75 and 25% of both Be and mg doping. The electronic structure of Be doped stanene show that the Fermi level is shifted towards the valance band edge when compared to pure stanene. The Dirac point of stanene locates at Γ shifted by 0.38 and 0.51eV for 6.25 and 12.5 %, an energy band gap of 0.27 and 0.50 eV were obtained above the Fermi level for 6.25 and 12.5% respectively. In the case of Mg, the bandgap remains slightly above the Fermi-level and amounts to 0.34 eV for 6.25 % and 0.43eV for 12.5 %, in the case of 18.75 and 25 % the Dirac cone disappear completely, an energy gap of 0.28 eV and 0.60 eV were obtained above the Fermi level for 6.25 and 12.5% respectively, our findings show that the band gap of stanene open at 12.5% doping concentration of both Be and Mg impurities. These obtained band-gap value seem to be sufficient for use of alkaline earth metal doped stanene in optoelectronic and such applications where stanene is incapacitate for its use to switch on/off devices.

Abstract Stanene (Sn)-based materials have been extensively applied in industrial production and daily life, but their potential biomedical application remains largely unexplored, which is due to the absence of the appropriate and effective methods for fabricating Sn-based biomaterials. Herein, we explored a new approach combining cryogenic exfoliation and liquid-phase exfoliation to successfully manufacture two-dimensional (2D) Sn nanosheets (SnNSs). The obtained SnNSs exhibited a typical sheet-like structure with an average size of ~ 100 nm and a thickness of ~ 5.1 nm. After PEGylation, the resulting PEGylated SnNSs (SnNSs@PEG) exhibited good stability, superior biocompatibility, and excellent photothermal performance, which could serve as robust photothermal agents for multi-modal imaging (fluorescence/photoacoustic/photothermal imaging)-guided photothermal elimination of cancer. Furthermore, we also used first-principles density functional theory calculations to investigate the photothermal mechanism of SnNSs, revealing that the free electrons in upper and lower layers of SnNSs contribute to the conversion of the photo to thermal. This work not only introduces a new approach to fabricate 2D SnNSs but also establishes the SnNSs-based nanomedicines for photonic cancer theranostics. This new type of SnNSs with great potential in the field of nanomedicines may spur a wave of developing Sn-based biological materials to benefit biomedical applications.

The adsorption behaviour of HCN molecule on a modified stanene substrate is investigated using first-principles calculation. The large adsorption distance, small adsorption energy and low charge transfer indicated that HCN molecule exhibits a weak physical adsorption mechanism on stanene. After introducing dopant and vacancy defects in the stanene substrate, the adsorption mechanism of HCN transformed into chemisorption. The significantly increased adsorption energy suggested that the interaction between the doped substrate and HCN was enhanced. Interestingly, the Cr-doped system not only exhibited a large charge transfer but also an intense magnetic performance. Our calculation results may provide useful information for fabricating stanene-based sensors. Highlights The adsorption of HCN on intact stanene is physical adsorption. The adsorption of HCN on vacancy defect stanene is chemisorption. The Cr doped vacancy-defected stanene is suitable for the HCN gas sensor. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials of perpendicular integration have recently emerged, which can be used to design novel electronic and optoelectronic devices. The heterostructures composed of stanene and blue phosphorene are investigated, the band structures and electronic properties of stanene/blue phosphorene are explored by using the First-principle calculation. It can be found that tuning the interlayer distance between stanene and blue phosphorene can effectively modulate the electronic structure of stanene/blue phosphorene heterostructures. The results show that the intrinsic electronic properties of stanene and blue phosphorene are well preserved in the unconstrained bilayers. Vertical positive and negative electric fields are applied in the heterostructure with electric fields between −0.6 and 0.7 V/Å, and the band gap increases with electric fields increasing. When in-plane biaxial tensile strain is applied, the band gap value increases with strain value increasing. The maximum band gap value is obtained at about strain 4%. When compressive strain is applied, the band gap decreases with the increase of the electric field and transforms to metallic at about strain −3%. The present work provides an effective way to tune the electronic structure and band gap of the stanene/blue phosphorene bilayer.

The electronic and dielectric properties of functionalized tin monolayers (stanene) using density‐functional theory and GW approximation are investigated. Charge density analysis of organic ligands adsorbed on stanene shows that these groups are able to induce a bandgap with parabolic bands in the originally metallic stanene. Furthermore, GW calculations demonstrate that the dielectric properties of functionalized stanene show adsorption in the visible region which can render stanene suitable for optoelectronic applications. [ABSTRACT FROM AUTHOR]

Two-dimensional materials have become one of the central research topics of scientists around the world after the production of graphene – a monatomic layer of carbon. Currently, two-dimensional crystals are among the most promising materials for next-generation nanoelectronics and photonics. The exploration of the feasibility of 2D materials devices causes a deeper insight into the physical properties of these new materials and provides a starting point for the development of a number of important practical areas. Over the past few years, researchers have been paying increased attention to graphene-like materials of group IVA elements, such as silicene (Si), germanene (Ge), stanene (Sn), and plumbene (Pb). Experimental production and study of the unique properties of two-dimensional monatomic layers of carbon, silicon, germanium, tin, and lead on various substrates created the prerequisites for the development of new generation devices based on them. The wide possibilities for controlling their exotic electronic, magnetic, and optical properties through the choice of the substrate, the design and geometry of the two-dimensional layer, as well as by controlling the magnitude of elastic stresses, have made them a dominating topic for studying in the field of nanotechnology and materials sciences. This paper reviews the latest advances in growing silicene, germanene, stanene, and plumbene using epitaxial methods. Growth technologies for creation of high-quality two-dimensional structures of large area required for promising instrumentation area are considered in more detail. [ABSTRACT FROM AUTHOR]

Abstract Graphene, an emerging fabric of carbon atoms, has manifested its versatility in all kinds of fields encompassing electronics, optoelectronics, thermoelectrics, taking advantage of its excellent mechanical strength, exceptional electronic and thermal conductivities, high surface specific area, and so forth. The prosperity of graphene never seen before has led the attention to silicene, siloxene, germanene, stanene, and plumbene due to their promising applications in the quantum spin Hall effect, topological insulator, batteries, capacitors, catalysis, and topological superconductivity. Herein, we review the existing production methods, numerous applications of two‐dimensional group‐IVA materials, and critically discuss the challenges of these materials, providing potential implications to the exploration of uncharted material systems.

The bandgap tuning of two-dimensional (2D) materials is a vital step for their potential applications in the realm of nanoelectronics, optoelectronics, and spintronics. In this context, the bandgap of cobalt (Co)-adsorbed nanoribbons of novel 2D materials (for instance, graphene (GNR), h-BN (BNNR), silicene (SiNR), germanene (GeNR), stanene (SnNR), and phosphorene (PNR)) is investigated under the effect of a transverse magnetic field via an acoustical deformation potential (ADP) scattering mechanism. Bandgaps ranging from 1.10 eV to 1.42 eV were obtained for Co-adsorbed 2D nanoribbons, which display semiconducting behaviour. In addition to that, investigating the impact of temperature on the bandgap revealed an anomalous temperature dependence of the bandgap. The outcomes of the present work would be advantageous for developing transition metal (TM)-adsorbed-nanoribbon-based nanoelectronic and spintronic devices, wherein controlling their bandgap by employing a magnetic field is a useful tool for advancing nanoribbon-based technology. [ABSTRACT FROM AUTHOR]

In this paper, the structural, electronic and magnetic properties of TM (TM = Zr, Mo, Nb) absorbed stanene with the adsorption of toxic gas molecules (CO, CO2, NO, NO2, SO2, and NH3) have been investigated using the first-principles calculations. The calculated results show that the adsorption of TM induces the magnetic properties of stanene, and the adsorption of gas molecule on TM-stanene can tune the magnetic moment. For the adsorption of CO, CO2 and NH3 on Nb-stanene, it can be clearly seen that the whole system represent half-metallic character. When six gas molecules are adsorbed on the Mo-stanene system, it is found that they all exhibit semiconducting properties. However, for the adsorption of NO and NO2 on the Zr-stanene system, it is shown that the whole system appears the transition from half-metallic character to metallic character. At the same time, it can be seen that the adsorption energy of TM-stanene with gas molecules adsorbed have increased by 3 ~ 5 times compared with that of pristine stanene monolayer, and the charge transfer have also significantly increased by 10 times. It indicates that TM-stanene with gas molecules adsorbed exhibit strong interactions, especially in the Zr-stanene system. Therefore, the TM-stanene is more suitable for gas molecules detection compared with the pristine stanene, and the calculated results suggest Zr-stanene is potential for gas sensing. This paper is expected to provide theoretical guidance for the design of toxic gas sensors.

The synthesis of new Xenes and their potential applications prototypes have achieved significant milestones so far. However, to date the realization of Xene heterostructures in analogy with the well known van der Waals heterostructures remains an unresolved issue. Here, a Xene heterostructure concept based on the epitaxial combination of silicene and stanene on Ag(111) is introduced, and how one Xene layer enables another Xene layer of a different nature to grow on top is demonstrated. Single‐phase (4 × 4) silicene is synthesized using stanene as a template, and stanene is grown on top of silicene on the other way around. In both heterostructures, in situ and ex situ probes confirm layer‐by‐layer growth without intercalations and intermixing. Modeling via density functional theory shows that the atomic layers in the heterostructures are strongly interacting, and hexagonal symmetry conservation in each individual layer is sequence selective. The results provide a substantial step toward currently missing Xene heterostructures and may inspire new paths for atomic‐scale materials engineering. [ABSTRACT FROM AUTHOR]

Stanene, composed of tin atoms, is a member of 2D-Xenes, two-dimensional single element materials. The properties of the stanene can be changed and improved by applying deformation, and it is important to know the range of in-plane deformation that the stanene can withstand. Using the Tersoff interatomic potential for calculation of phonon frequencies, the range of stability of planar stanene under uniform in-plane deformation is analyzed and compared with the known data for graphene. Unlike atomically flat graphene, stanene has a certain thickness (buckling height). It is shown that as the tensile strain increases, the thickness of the buckled stanene decreases, and when a certain tensile strain is reached, the stanene becomes absolutely flat, like graphene. Postcritical behaviour of stanene depends on the type of applied strain: critical tensile strain leads to breaking of interatomic bonds and critical in-plane compressive strain leads to rippling of stanene. It is demonstrated that application of shear strain reduces the range of stability of stanene. The existence of two energetically equivalent states of stanene is shown, and consequently, the possibility of the formation of domains separated by domain walls in the stanene is predicted.

Stanene is one of the most intriguing two-dimensional (2D) materials because of its nontrivial topological properties. Here, the optical properties from THz to UV of molecular beam deposited tin nanosheets on Al2O3(0001) are reported. The experimental absorption coefficient cannot be described in terms of metallic tin or tin oxides. Nonetheless, a similar optical behavior was predicted by theory for freestanding stanene, thus suggesting the formation of the 2D tin nanosheets with stanene-like properties. These findings show that 2D tin bears appealing optical properties in a broad range of the electromagnetic spectrum, thus paving the way to Xenes-based nanophotonics. [ABSTRACT FROM AUTHOR]

Ultrasound (US)‐mediated sonodynamic therapy (SDT) has emerged as a superior modality for cancer treatment owing to the non‐invasiveness and high tissue‐penetrating depth. However, developing biocompatible nanomaterial‐based sonosensitizers with efficient SDT capability remains challenging. Here, we employed a liquid‐phase exfoliation strategy to obtain a new type of two‐dimensional (2D) stanene‐based nanosheets (SnNSs) with a band gap of 2.3 eV, which is narrower than those of the most extensively studied nano‐sonosensitizers, allowing a more efficient US‐triggered separation of electron (e−)‐hole (h+) pairs for reactive oxygen species (ROS) generation. In addition, we discovered that such SnNSs could also serve as robust near‐infrared (NIR)‐mediated photothermal therapy (PTT) agents owing to their efficient photothermal conversion, and serve as nanocarriers for anticancer drug delivery owing to the inherent 2D layered structure. This study not only presents general nanoplatforms for SDT‐enhanced combination cancer therapy, but also highlights the utility of 2D SnNSs to the field of nanomedicine. [ABSTRACT FROM AUTHOR]

Highlights: 2D Sn nanosheets (SnNSs) were prepared through the combination of cryogenic exfoliation and liquid-phase exfoliation. The functionalized 2D SnNSs have good stability, superior biocompatibility, high photothermal conversion efficiency, and multimode imaging capability.Stanene (Sn)-based materials have been extensively applied in industrial production and daily life, but their potential biomedical application remains largely unexplored, which is due to the absence of the appropriate and effective methods for fabricating Sn-based biomaterials. Herein, we explored a new approach combining cryogenic exfoliation and liquid-phase exfoliation to successfully manufacture two-dimensional (2D) Sn nanosheets (SnNSs). The obtained SnNSs exhibited a typical sheet-like structure with an average size of ~ 100 nm and a thickness of ~ 5.1 nm. After PEGylation, the resulting PEGylated SnNSs (SnNSs@PEG) exhibited good stability, superior biocompatibility, and excellent photothermal performance, which could serve as robust photothermal agents for multi-modal imaging (fluorescence/photoacoustic/photothermal imaging)-guided photothermal elimination of cancer. Furthermore, we also used first-principles density functional theory calculations to investigate the photothermal mechanism of SnNSs, revealing that the free electrons in upper and lower layers of SnNSs contribute to the conversion of the photo to thermal. This work not only introduces a new approach to fabricate 2D SnNSs but also establishes the SnNSs-based nanomedicines for photonic cancer theranostics. This new type of SnNSs with great potential in the field of nanomedicines may spur a wave of developing Sn-based biological materials to benefit biomedical applications. [ABSTRACT FROM AUTHOR]

Heterostacks formed by combining two-dimensional materials show novel properties which are of great interest for new applications in electronics, photonics and even twistronics, the new emerging field born after the outstanding discoveries on twisted graphene. Here, we report the direct growth of tin nanosheets at the two-dimensional limit via molecular beam epitaxy on chemical vapor deposited graphene on Al 2 O 3 (0001). The mutual interaction between the tin nanosheets and graphene is evidenced by structural and chemical investigations. On the one hand, Raman spectroscopy indicates that graphene undergoes compressive strain after the tin growth, while no charge transfer is observed. On the other hand, chemical analysis shows that tin nanosheets interaction with sapphire is mediated by graphene avoiding the tin oxidation occurring in the direct growth on this substrate. Remarkably, optical measurements show that the absorption of tin nanosheets exhibits a graphene-like behavior with a strong absorption in the ultraviolet photon energy range, therein resulting in a different optical response compared to tin nanosheets on bare sapphire. The optical properties of ultra-thin tin films therefore represent an open and flexible playground for the absorption of light in a broad range of the electromagnetic spectrum and technologically relevant applications for photon harvesting and sensors., (Creative Commons Attribution license.)

Experimental fabrication and investigation of unique properties of two-dimensional monoatomic layers of carbon, silicon, germanium, and tin on different surfaces have opened bright perspectives for development of devices of new generation. Wide opportunities to control their exotic electronic and optical properties via appropriate choice of substrate, content and geometry of two-dimensional layer, combined with elastic strain engineering, made them the central theme of research in the field of nanotechnology and materials science. In this work we review epitaxial methods of synthesis of two-dimensional materials of group IV elements: silicene, germanene, and stanene. General structural properties of these materials are also briefly considered. Special attention is paid to the technological growth modes, providing fabrication of high-quality large-area two-dimensional structures necessary for emerging device application. [ABSTRACT FROM AUTHOR]

The energetic and electronic properties of stanene nanomeshes (SnNMs) under biaxial strain are investigated by using first-principles density functional theory. The results of this exploratory study indicate that SnNMs are stable and that, when the width W of the wall between neighboring holes is even, a bandgap can be opened, indicating that SnNMs can be used in logic applications. The value of the bandgap decreases with increasing W and shows a simple relation with the ratio of the removed to total Sn atoms of stanene. It is found that the application of biaxial strain can effectively lower the energy of formation and tune the bandgap of SnNMs. Both compressive and tensile strain can lower the energy of formation, while only compressive strain can increase the bandgap, which is more favorable for use in logic applications. These results reveal that SnNMs have significant potential for use in electronic applications, especially when applying strain engineering. [ABSTRACT FROM AUTHOR]

Two dimensional (2D) topological insulators (TIs) and topological superconductors (TSCs) have been intensively studied for recent years due to their great potential for dissipationless electron transportation and fault-tolerant quantum computing, respectively. Here we focus on stanene, the tin analogue of graphene, to give a brief review of their development as a candidate for both 2D TI and TSC. Stanene is proposed to be a TI with a large gap of 0.3 eV, and its topological properties are sensitive to various factors, e.g., the lattice constants, chemical functionalization and layer thickness, which offer various methods for phase tunning. Experimentally, the inverted gap and edge states are observed recently, which are strong evidences for TI. In addition, stanene is also predicted to be a time reversal invariant TSC by breaking inversion symmetry, supporting helical Majorana edge modes. The layer-dependent superconductivity of stanene is recently confirmed by both transport and scanning tunneling microscopy measurements. This review gives a detailed introduction to stanene and its topological properties and some prospects are also discussed. [ABSTRACT FROM AUTHOR]

In this study, we performed a density functional theory based investigation of the structural, electronic, and optical properties of a stanane, fully hydrogenated stanene SnH, and armchair stanane nanoribbons ASnHNRs. Our full geometry optimization calculations show stanane has 0.84 Å buckled height and the buckled structure is preserved in ASnHNRs. The optimized lattice parameter of stanane, Sn–Sn, and Sn–H bond length are 4.58 Å, 2.75Å, and 1.73 Å, respectively. Electronic structure calculations show that stanane is a moderate-band-gap semiconductor with a direct band gap of 1.2 eV and ASnHNRs are wide-band-gap semiconductors. The band gap of ASnHNRs decreases as the ribbons width increases. We investigated the optical properties for two directions of polarization. For perpendicular-polarized light, the imaginary part of dielectric function ε 2 (ω) of stanane peaks between 5 and 10 eV; while for the parallel-polarized light, the peaks are seen in a wide range of energy. According to the results, stanane is a good absorptive matter, especially for visible regions of the electromagnetic spectrum. The presence of anisotropy with respect to the type of light polarization is observed in ASnHNRs also. In these structures, the main peak of ε 2 (ω) is located at 3.4 eV for parallel- and in 6–8 eV for perpendicular-polarized light. [ABSTRACT FROM AUTHOR]

Group 14 elemental post‐graphene materials receive much attention because of their outstanding properties, typically, as robust 2D topological insulators. Their heterostructures are a main target in view of disruptive applications. Here, the realization of striking in‐plane lateral heterostructures between germanene and stanene are shown, which are sustainable 2D Ge‐ and Snbased graphene analogs, but with a strong intrinsic spin–orbit coupling. A unique combination of atomic segregation epitaxy (ASE) and molecular beam epitaxy (MBE) for the in situ continuous fabrication of nearly atomically precise lateral multijunction heterostructures, respectively, consisting of atom‐thin germanene and stanene on a Ag(111) thin film is used. Scanning tunneling microscopy (STM) observations at atomic scale and low‐energy electron diffraction testify that germanene and stanene sheets without intermixing are prepared simultaneously on the same terraces at wide scale: tin and germanium atoms neither exchange their sites nor adsorb on the germanene and stanene sheets. The atomic structure of the boundary between germanene and stanene is derived from STM images, while scanning tunneling spectroscopy reveals key electronic features at the heterojunction. This innovative synergetic approach of ASE and MBE growths offers great flexibility for the realization of unprecedented lateral 2D heterostructures. [ABSTRACT FROM AUTHOR]

Z 2 topology in two-dimensional group IVA materials has been explained by the band orders due to the crystal field splitting at the Γ point in the Brillouin zone, while spin-orbit coupling (SOC) was considered just to open a band gap. By using a multi-orbital tight-binding model, we show that the SOC induces band inversion between the conduction and valence bands at the Γ point in plumbene, which also is the case in stanene when the SOC strength increases. As a result of the band inversion, plumbene becomes a spin Chern insulator with a spin Chern number C S = 2 and, as the SOC strength increases, stanene undergoes a topological phase transition from a Z 2 topological insulator to a spin Chern insulator with C S = 2. Under a staggered AB-sublattice potential, plumbene undergoes a phase transition from the spin Chern insulator with C S = 2 to a Z 2 topological insulator with C S = 1. • Spin-orbit coupling induced band inversion of conduction and valence bands in plumbene and stanene. • Plumbene and stanene become spin Chern insulators as a result of the band inversion. • Phase transition from spin Chern insulator topological insulator with under staggered sublattice potential. [ABSTRACT FROM AUTHOR]

Graphene, an emerging fabric of carbon atoms, has manifested its versatility in all kinds of fields encompassing electronics, optoelectronics, thermoelectrics, taking advantage of its excellent mechanical strength, exceptional electronic and thermal conductivities, high surface specific area, and so forth. The prosperity of graphene never seen before has led the attention to silicene, siloxene, germanene, stanene, and plumbene due to their promising applications in the quantum spin Hall effect, topological insulator, batteries, capacitors, catalysis, and topological superconductivity. Herein, we review the existing production methods, numerous applications of two‐dimensional group‐IVA materials, and critically discuss the challenges of these materials, providing potential implications to the exploration of uncharted material systems. [ABSTRACT FROM AUTHOR]

It is essential to understand to what extent the protected edge states of topological insulators (TIs) can survive against the degradation of the ubiquitous disorders in realistic devices. From a different perspective, disorders can also help to enrich the applications by modulation of the phases in TIs. In this work, the phases and phase transitions in stanene, a two-dimensional TI, have been investigated via the statistical approach based on the random matrix theory. Using a tight binding model with Aderson disorder term and the Landauer-Büttiker formalism, we calculated the conductance of realistic stanene ribbons of tens of nanometers long with random disorders. The calculated phase diagram presents TI in the gap, metal in high energy and ordinary insulator in large disorder region. Increasing the width of the ribbon can significantly enhance the robustness of TI phase against disorders. Due to different underlying symmetries, the metallic phase can be further categorized into unitary and orthogonal classes according to the calculated universal conductance fluctuations. The local density of states is calculated, showing characteristic patterns, which can facilitate the experimental identification of the phases. It is found that different phases have distinguishing statistical distribution of conductance. Whereas at the phase boundary the distribution exhibits intermediate features to show where the phase transition occurs. To reveal the phase evolution process, we further studied the effects of the disorders on respective transmission channels. It is found that when phase transition takes place, the major transmission channels of the old phase are fading and the new channels of the new phase are emerging., (© 2024 IOP Publishing Ltd.)

Adsorption of noble metals (Ag, Au, Pd and Pt) on the pristine stanene monolayers was investigated using the density functional theory calculations. Three different adsorption positions of noble metals on the stanene monolayer were considered, namely the top, valley and hollow sites. The structural stability of the metal adsorbed systems were discussed in term of adsorption energies. The results predict that the adsorption of noble metals on the hollow site of the stanene hexagon is more energetically favorable than that on the top and valley sites. Charge density difference calculations show that the charges were mainly accumulated over the adsorbed noble metals. The significant overlaps between the PDOS spectra of the noble metal and tin atoms indicate the formation of chemical bonds between them. Charge analysis based on Hirshfeld net atomic charges reveals a noticeable charge transfer from the stanene sheet to the adsorbed noble metals. Furthermore, the band structure calculations confirm that Ag and Au adsorbed stanene systems exhibit metallic behavior, whereas Pd and Pt adsorbed ones show semiconductor characteristics. The inclusion of SOC effect does not change the electronic phase of the systems, while the band gap gets narrower. The results confirm that noble metal embedded stanene monolayer can be used as effective and potential candidates for application in next-generation nanoelectronic devices. [ABSTRACT FROM AUTHOR]

Abstract Stanene is a quantum spin Hall insulator and a promising material for optoelectronic and electronic devices. Density functional theoretical (DFT) calculations are performed to understand the effect of elemental doping (In, Sb, and In Sb) towards gas sensor and photocatalytic applications. The In/Sb doping in stanene enhances the formation of Lewis acid-base adducts with N-based gas molecules, which in turn improves the sensitivity and selectivity towards a particular gas molecule. Moreover, such stanene based systems show excellent energetic, thermal, dynamical, and mechanical stability and band edge potential, which further suggests that they can be synthesized and used for various applications. Graphical abstract In@, Sb@ and In-Sb@stanene has been reported for the gas sensing and photocatalytic applications. The In/Sb doping in stanene (In/Sb@stanene) enhances the formation of Lewis-acid base adducts with N-based gas molecules. Such Lewis acid-base adduct formation plays an important role to improve the selectivity and sensitivity of doped stanene towards particular gas molecules. Unlabelled Image Highlights • Doping of stanene with elemental (In, Sb, and In Sb) changes the electronic properties in stanene. • The In/Sb doping in stanene (In/Sb@stanene) enhances the formation of Lewis-acid base adducts with N-based gas molecules. • Such Lewis-acid base adducts formation improves the sensitivity and selectivity towards NO 2 gas molecule. • Such doped stanene systems are promising for photocatalytic applications over graphene. [ABSTRACT FROM AUTHOR]

In this study, we have performed non-equilibrium molecular dynamics simulation (NEMD) to the interface thermal transport in silicene/stanene hetero-structures, which include the effect of structure size, temperature and defects on the thermal conductance G. The results show that G increases with the temperature significantly, while almost keep constant with the variable of the size of structure. The vacancy defects will lead to the decrease of saturated thermal conductance compared with the defect-free one, which is ascribed to the enhancement of phonon inversion process and the scattering concentration of the phonons. In particular, a singularity point of thermal conductance is found when a single vacancy defect is set in the interface of stanene with the vacancy defect moving. Our result indicates that the thermal conductance of silicene/stanene hetero-structures present remarkable properties (low size dependence and singularities exist as defects move) and are promising for applications of the low dimensional silicene/stanene nanostructure based thermal and nanoelectronic devices. • We for the first time investigate the interface thermal conductivity between stanene and siliene. • Size dependence on the thermal conductivity of the interface between stanene and siliene is proved to be low. • The interface thermal conductivity can be improved by increasing temperature. • The interface thermal conductivity can be changed by setting the defect position. [ABSTRACT FROM AUTHOR]

Abstract Stanene, two-dimensional, graphene-like buckled honeycomb structure, has been deemed as a potential material for the next generation nano-electronics application. In electronic applications, the materials are subjected to both thermal and mechanical loadings. In addition, structural defects are inevitable during synthesis of nanomaterials. Therefore, it is essential to study the mechanical and thermal properties of stanene with various structural defects. We investigated the effects of point vacancy, bivacancy and Stone-Wales defects on tensile response and thermal transport of single-layer bulk stanene sheets using classical molecular dynamics (MD) simulations. MEAM potential is used to describe the inter-atomic forces in order to predict the properties of the stanene adequately. We probed the deformation process of defective bulk stanene by applying uniaxial tensile loading. Our study suggests that tensile strength and elastic modulus of stanene decrease with the increment of defect concentrations. Moreover, stanene sheet with Stone-Wales defect shows less in-plane stiffness to the loading. Using non-equilibrium molecular dynamics (NEMD) method, we found that, the phonon thermal conductivity of stanene is highly sensitive to defect concentrations. Only 0.1% of defect concentrations result in about 40% reduction in thermal conductivity. To elucidate the underlying mechanism responsible for this reduction, vibrational density of states (vDOS) are calculated. Overall, our reported results provide an insight into the effect of defects in mechanical and thermal properties of defective bulk stanene and will facilitate further tailoring of the design of stanene based nanoelectronics device. Highlights • Effect of defects on mechanical and thermal transport of bulk stanene are investigated using Molecular Dynamics simulations. • Deformation processes of defective bulk stanene are investigated to interpret the failure mechanism in details. • With higher probabilities of formation, Stone-Wales defects in bulk stanene show less inplane stiffness to the loading. • Point vacancy case has the highest tensile strength and bivacancy along zigzag directional loading shows double yield point. • A very small percentage of defects concentration results in almost 40% reduction of thermal transport properties. [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract The adsorption of phenol, hydrazine and thiophene molecules on the stanene monolayers were investigated using the density functional theory calculations. Various adsorption positions of molecules on the stanene monolayers were tested. The properties of the adsorption systems were investigated in terms of adsorption distance, adsorption energy, band structures, molecular orbitals, charge density difference (CDD) and projected density of states (PDOS). Adsorption energy results indicate that the adsorption of phenol, hydrazine and thiophene molecules on the stanene is energetically favorable. Phenol and thiophene molecules show a weak physisorption on the stanene monolayers due to the lack of covalent bond at the interface region, whereas hydrazine exhibits chemisorption on the stanene sheet. The adsorption of phenol, hydrazine and thiophene molecules induces a narrow band gap at the Fermi level of stanene, leading to the semiconductor property of the combined system (stanene + adsorbate). The adsorption of hydrazine on the surface makes a more significant change on the electronic properties of stanene than that of phenol and thiophene. The large PDOS overlaps between the PDOS spectra of the tin and nitrogen atoms indicate the formation of chemical bonds between these atoms. The charge density difference calculations represent charge accumulation on the adsorbed molecules. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Hot carriers are studied in stanene to adapt this material to specific applications. • Electron-phonon coupling vary strongly along crystallographic directions. • Electron linewidth depends mainly on the out-of-plane optical phonon modes. • Linewidth and hot electrons lifetime are determined. Abstract Collecting carriers before they thermalize is the main goal for carrier's cells. This work presents a study on hot carriers in stanene using density functional and many-body perturbation theories. The present approach is applied to investigate the electron linewidth from electron-phonon interaction at 0 K and 300 K. It is shown that electron-phonon linewidth in stanene displays an important temperature dependence as a function of electron energy. Two different cases are considered in this report, first for electron state initially at the valence band maximum and second at the conduction band minimum. It is found that the electron-phonon interaction is strongly dependent on the electron wave vector. This orientation dependence can be used as a basis for transport phenomena. The electron scattering rate at room temperature, projected on the six phonons modes, reveals that the contribution is overall dominated by out-of-plane transversal optical modes (ZO). Another finding is that stanene's hot carriers thermalize at 250 fs, which is faster than in graphene. This study paves the way to explore hot electrons that are difficult to achieve in experiment. [ABSTRACT FROM AUTHOR]

Properties of Sn/BeO heterostructure formed with beryllium oxide (BeO) monolayer and 2D stanene (Sn) is studied in this work. The first-principle study is employed here to systematically investigate the structural stability and electrical properties of the Sn/BeO heterostructure. The results from simulations reveal that the introduction of BeO not only leads to a significant bandgap opening of 98 meV, but it also retains the various intrinsic electrical properties of stanene to a large extent. The effect of spin-orbit coupling (SOC) is studied both in pristine stanene as well as in Sn/BeO heterostructure. The Sn/BeO heterostructure shows the Rashba-type of spin-splitting under SOC, which is very promising for application in spintronic devices. Moreover, it is also observed that the bandgap can be tuned by applying external strain and electric field, while the characteristic Dirac cone is maintained throughout. The application of an external electric field is found to be more effective in bandgap modulation. It leads to a linear change in the bandgap, with a bandgap value of 402 meV for 4 V nm ^−1 . The results obtained from our study indicate that Sn/BeO heterostructure can be a suitable material for the development of spintronic devices.

Stanene is one of the most important quantum spin hall insulators and can be considered as an efficient material for the fabrication electronic and optoelectronic devices and next-generation integrated circuits. Density functional theory calculations were carried out to investigate the band gap variations in stanene, and the effects of elemental doping were taken into account. For the pristine stanene sheet, the valence and conduction bands of stanene consist of Sn 5p orbitals. The pristine stanene system is a zero band gap material with a Dirac cone located at the K point. The Al-doped, B-doped, N-doped and P-doped systems show metallic characteristics. In the Al-doped and B-doped stanene, the Fermi level is shifted towards the valence band edge, while in the N-doped and P-doped ones, the Fermi level shifts towards the conduction band edge. These doped systems behave as degenerate semiconductors, due to the significant shifts in the Fermi levels. Other doping elements such as Si and Ge were also considered in this study. Both Si and Ge-doped stanene show the properties similar to the pristine stanene, which is a consequence of the similar electronic structure of Si, Ge and Sn atoms. In the N-doped stanene, the Dirac cone vanishes, whereas in the other doping patterns, the Dirac cone exists around the Fermi level. The electronic band structure of the Si and Ge-doped systems is principally the same as that of pristine one. Our results thus suggest a theoretical basis for the potential application of such doped systems in electronic and optoelectronic devices. [ABSTRACT FROM AUTHOR]

Using ab initio calculation, structural stability, including electronic properties of bare/hydrogenated stanene (BSn/HSn) nanosheet, was explored. The geometrical stability of HSn material is verified with the influence of phonon band structure and formation energy. The concentration of the present work is to check the quality of Musa acuminata (banana) fruits when it is in ripe and overripe stage using HSn nanosheet material. Further, the interaction of different volatile organic compounds, namely, isoamyl acetate, isobutyl acetate, acetoin, and 2,3-butanediol aromas on HSn base material is studied with the significant parameter such as Bader charge transfer, band gap, adsorption energy, and average energy band gap changes. The sensitivity of the aromas emitting from ripe and overripe stages of banana on HSn nanosheet was studied using density of states spectrum. The adsorption energy of HSn nanosheet is found in the range of − 0.055 to − 0.989 eV upon the interaction VOCs of Musa acuminata. The novel aspect of the present work is to check the quality of Musa acuminata with the influence of HSn nanosheet using density functional theory. [ABSTRACT FROM AUTHOR]