Epitaxial Growth and Band Structure of Te Film on Graphene

Direct Observations of Spontaneous In-Plane Electronic Polarization in 2D Te Films

Single-element polarization in low dimensions is fascinating for constructing next-generation nanoelectronics with multiple functionalities, yet remains difficult to access with satisfactory performance. Here, spectroscopic evidences are presented for the spontaneous electronic polarization in tellurium (Te) films thinned down to bilayer, characterized by low-temperature scanning tunneling microscopy/spectroscopy. The unique chiral structure and centrosymmetry-breaking character in 2D Te gives rise to sizable in-plane polarization with accumulated charges, which is demonstrated by the reversed band-bending trends at opposite polarization edges in spatially resolved spectra and conductance mappings. The polarity of charges exhibits intriguing influence on imaging the moiré superlattice at the Te-graphene interface. Moreover, the plain spontaneous polarization robustly exists for various film thicknesses, and can universally preserve against different epitaxial substrates. The experimental validations of considerable electronic polarization in Te multilayers thus provide a realistic platform for promisingly facilitating reliable applications in microelectronic devices.

Growth of Single Crystalline 2D Materials beyond Graphene on Non-metallic Substrates

The advent of 2D materials has ushered in the exploration of their synthesis, characterization and application. While plenty of 2D materials have been synthesized on various metallic substrates, interfacial interaction significantly affects their intrinsic electronic properties. Additionally, the complex transfer process presents further challenges. In this context, experimental efforts are devoted to the direct growth on technologically important semiconductor/insulator substrates. This review aims to uncover the effects of substrate on the growth of 2D materials. The focus is on non-metallic substrate used for epitaxial growth and how this highlights the necessity for phase engineering and advanced characterization at atomic scale. Special attention is paid to monoelemental 2D structures with topological properties. The conclusion is drawn through a discussion of the requirements for integrating 2D materials with current semiconductor-based technology and the unique properties of heterostructures based on 2D materials. Overall, this review describes how 2D materials can be fabricated directly on non-metallic substrates and the exploration of growth mechanism at atomic scale.

Continuous Template Growth of Large-Scale Tellurene Films on 1T'-MoTe2

Use of a template triggers an epitaxial interaction with the depositing material during synthesis. Recent studies have demonstrated that two-dimensional tellurium (tellurene) can be directionally oriented when grown on transition metal dichalcogenide (TMD) templates. Specifically, employing a T-phase TMD, such as WTe2, restricts the growth direction even further due to its anisotropic nature, which allows for the synthesis of well-oriented tellurene films. Despite this, producing large-area epitaxial films still remains a significant challenge. Here, we report the continuous synthesis of a 1T'-MoTe2 template via chemical vapor deposition and tellurene via vapor transport. The interaction between helical Te and the 1T'-MoTe2 template facilitates the Te chains to collapse into ribbon shapes, enhancing lateral growth at a rate approximately 6 times higher than in the vertical direction, as confirmed by scanning electron microscopy and atomic force microscopy. Interestingly, despite the predominance of the lateral growth, cross-sectional transmission electron microscopy analysis of the tellurene ribbons revealed a consistent 60-degree incline at the edges. This suggests that the edges of the tellurene ribbons, where they contact the template surface, are favorable sites for additional Te absorption, which then stacks along the incline angle to expand. Furthermore, controlling the synthesis temperature, duration, and preheating time has facilitated the successful synthesis of tellurene films. The resultant tellurene exhibited hole mobility as high as ∼400 cm2/V s. After removing the underlying metallic template with plasma treatment, the film showed a current on/off ratio of ∼103. This ratio was confirmed by two-terminal field-effect transistor measurements and supported by near-field terahertz (THz) spectroscopy mapping.

Realization of Honeycomb Tellurene with Topological Edge States

The two-dimensional (2D) honeycomb lattice has attracted intensive research interest due to the appearance of Dirac-type band structures as the consequence of two sublattices in the honeycomb structure. Introducing strong spin-orbit coupling (SOC) leads to a gap opening at the Dirac point, transforming the honeycomb lattice into a 2D topological insulator as a platform for the quantum spin Hall effect (QSHE). In this work, we realize a 2D honeycomb-structured film with tellurium, the heaviest nonradioactive element in Group VI, namely, tellurene, via molecular beam epitaxy. We revealed the gap opening of 160 meV at the Dirac point due to the strong SOC in the honeycomb-structured tellurene by angle-resolved photoemission spectroscopy. The topological edge states of tellurene are detected via scanning tunneling microscopy/spectroscopy. These results demonstrate that tellurene is a novel 2D honeycomb lattice with strong SOC, and they unambiguously prove that tellurene is a promising candidate for a room-temperature QSHE system.

Strain controllable band alignment and the interfacial and optical properties of tellurene/GaAs van der Waals heterostructures

By using first principles calculations, we theoretically investigate the electronic structures and the interfacial and optical properties of the two-dimensional tellurene (Te)-gallium arsenide (GaAs) van der Waals heterostructures (vdWHs), i.e., α-Te/GaAs and γ-Te/GaAs, formed using Te and GaAs monolayers. It has been demonstrated that, the semiconductor-semiconductor contacted α-Te/GaAs vdWH exhibits a type-II band alignment with a direct band gap of 0.28 eV while the metal-semiconductor contacted γ-Te/GaAs vdWH has a p-type Schottky contact with a Schottky barrier height (SBH) of 0.36 eV at the interface. The transition from type-II to type-III band alignment is observed firstly in the α-Te/GaAs vdWH when the in-plane biaxial strain is less than -5.2% and larger than 4.4%, meanwhile, the p-type Schottky contact to Ohmic contact transition may be realized in the γ-Te/GaAs vdWH when the in-plane biaxial strain is less than -2.4%. Finally, the maximum optical absorption coefficients of the α- and γ-Te/GaAs vdWHs have been found to be up to 31% and 29%, respectively, and may be modulated effectively by applying in-plane biaxial strain. The obtained results may be of importance in the design of nanoelectronic devices based on the proposed tellurene/GaAs vdWHs.

Wet-Chemical Synthesis of Elemental 2D Materials

Wet-chemical synthesis refers to the bottom-up chemical synthesis in solution, which is among the most popular synthetic approaches towards functional two-dimensional (2D) materials. It offers several advantages, including cost-effectiveness, high yields,, precious control over the production process. As an emerging family of 2D materials, elemental 2D materials (Xenes) have shown great potential in various applications such as electronics, catalysts, biochemistry,, sensing technologies due to their exceptional/exotic properties such as large surface area, tunable band gap,, high carrier mobility. In this review, we provide a comprehensive overview of the current state-of-the-art in wet-chemical synthesis of Xenes including tellurene, bismuthene, antimonene, phosphorene,, arsenene. The current solvent compositions, process parameters utilized in wet-chemical synthesis, their effects on the thickness, stability of the resulting Xenes are also presented. Key factors considered involves ligands, precursors, surfactants, reaction time, temperature. Finally, we highlight recent advances, existing challenges in the current application of wet-chemical synthesis for Xenes production, provide perspectives on future improvement.

Surfactant-Free Ultrasonication-Assisted Synthesis of 2d Tellurium Based on Metastable 1T'-MoTe2

Elemental 2D materials (E2DMs) have been attracting considerable attention owing to their chemical simplicity and excellent/exotic properties. However, the lack of robust chemical synthetic methods seriously limits their potential. Here, a surfactant-free liquid-phase synthesis of high-quality 2D tellurium is reported based on ultrasonication-assisted exfoliation of metastable 1T'-MoTe2. The as-grown 2D tellurium nanosheets exhibit excellent single crystallinity, ideal 2D morphology, surfactant-free surface, and negligible 1D by-products. Furthermore, a unique growth mechanism based on the atomic escape of Te atoms from metastable transition metal dichalcogenides and guided 2D growth in the liquid phase is proposed and verified. 2D tellurium-based field-effect transistors show ultrahigh hole mobility exceeding 1000 cm2 V-1 s-1 at room temperature attributing to the high crystallinity and surfactant-free surface, and exceptional chemical and operational stability using both solid-state dielectric and liquid-state electrical double layer. The facile ultrasonication-assisted synthesis of high-quality 2D tellurium paves the way for further exploration of E2DMs and expands the scope of liquid-phase exfoliation (LPE) methodology toward the controlled wet-chemical synthesis of functional nanomaterials.

Phase-engineered synthesis of atomically thin te single crystals with high on-state currents

Multiple structural phases of tellurium (Te) have opened up various opportunities for the development of two-dimensional (2D) electronics and optoelectronics. However, the phase-engineered synthesis of 2D Te at the atomic level remains a substantial challenge. Herein, we design an atomic cluster density and interface-guided multiple control strategy for phase- and thickness-controlled synthesis of α-Te nanosheets and β-Te nanoribbons (from monolayer to tens of μm) on WS2 substrates. As the thickness decreases, the α-Te nanosheets exhibit a transition from metallic to n-type semiconducting properties. On the other hand, the β-Te nanoribbons remain p-type semiconductors with an ON-state current density (ION) up to ~ 1527 μA μm-1 and a mobility as high as ~ 690.7 cm2 V-1 s-1 at room temperature. Both Te phases exhibit good air stability after several months. Furthermore, short-channel (down to 46 nm) β-Te nanoribbon transistors exhibit remarkable electrical properties (ION = ~ 1270 μA μm-1 and ON-state resistance down to 0.63 kΩ μm) at Vds = 1 V.

Tunability of electronic properties in the 2D MoS2/α-tellurene/WS2 heterotrilayer via biaxial strain and electric field

Alpha-tellurene (α-Te), a two-dimensional (2D) material that has been theoretically predicted and experimentally verified, has garnered significant attention due to its unique properties. In this study, we investigated the 2D trilayer MoS2/α-Te/WS2 van der Waals heterostructure with different stacking orders using first-principles calculations. Our results indicate that this heterotrilayer exhibits an intrinsic type-I band alignment and an indirect band gap similar to that of monolayer α-Te. Notably, the band edges of the heterostructure can be modulated by biaxial strain and an external electric field, enabling these edges to arise from different monolayers. This controlled manipulation facilitates the effective separation of photogenerated electron-hole pairs and prolongs the carrier lifetime. Moreover, the heterostructure can undergo a transition from an indirect to a direct band gap under biaxial compressive strain or a moderate negative electric field, and semiconductor-to-metal transition can also be achieved by intensifying the biaxial strain and external electric field. Overall, our research provides valuable theoretical insights into the potential applications of α-Te-based heterostructures, rendering them promising candidates for the next generation of nanodevices.

Experimental Realization of Monolayer α-Tellurene

2D materials emerge as a versatile platform for developing next-generation devices. The experimental realization of novel artificial 2D atomic crystals, which does not have bulk counterparts in nature, is still challenging and always requires new physical or chemical processes. Monolayer α-tellurene is predicted to be a stable 2D allotrope of tellurium (Te), which has great potential for applications in high-performance field-effect transistors. However, the synthesis of monolayer α-tellurene remains elusive because of its complex lattice configuration, in which the Te atoms are stacked in tri-layers in an octahedral fashion. Here, a self-assemble approach, using three atom-long Te chains derived from the dynamic non-equilibrium growth of an a-Si:Te alloy as building blocks, is reported for the epitaxial growth of monolayer α-tellurene on a Sb2 Te3 substrate. By combining scanning tunneling microscopy/spectroscopy with density functional theory calculations, the surface morphology and electronic structure of monolayer α-tellurene are revealed and the underlying growth mechanism is determined. The successful synthesis of monolayer α-tellurene opens up the possibility for the application of this new single-element 2D material in advanced electronic devices.

Controlled Growth of Submillimeter-Scale Cr5Te8 Nanosheets and the Domain Wall Nucleation Governed Magnetization Reversal Process

Two-dimensional (2D) ferromagnets have attracted widespread attention for promising applications in compact spintronic devices. However, the controlled synthesis of high-quality, large-sized, and ultrathin 2D magnets via facile, economical method remains challenging. Herein, we develop a hydrogen-tailored chemical vapor deposition approach to fabricating 2D Cr5Te8 ferromagnetic nanosheets. Interestingly, the time period of introducing hydrogen was found to be crucial for controlling the lateral size, and a Cr5Te8 single-crystalline nanosheet of lateral size up to ∼360 μm with single-unit-cell thickness has been obtained. These samples exhibit a leading role of domain wall nucleation in governing the magnetization reversal process, providing important references for optimizing the performances of associated devices. The nanosheets also show notable magnetotransport response, including nonmonotonous magnetic-field-dependent magnetoresistance and sizable anomalous Hall resistivity, demonstrating Cr5Te8 as a promising material for constructing high-performance magnetoelectronic devices. This study presents a breakthrough of large-sized CVD-grown 2D magnetic materials, which is indispensable for constructing 2D spintronic devices.

Epitaxial Growth of 2D Binary Phosphides

Combinations of phosphorus with main group III, IV, and V elements are theoretically predicted to generate 2D binary phosphides with extraordinary properties and promising applications. However, experimental synthesis is significantly lacking. Here, a general approach for preparing 2D binary phosphides is reported using single crystalline surfaces containing the constituent element of target 2D materials as the substrate. To validate this, SnP3 and BiP, representing typical 2D binary phosphides, are successfully synthesized on Cu2 Sn and bismuthene, respectively. Scanning tunneling microscopy imaging reveals a hexagonal pattern of SnP3 on Cu2 Sn, while α-BiP can be epitaxially grown on the α-bismuthene domain on Cu2 Sb. First-principles calculations reveal that the formation of SnP3 on Cu2 Sn is associated with strong interface bonding and significant charge transfer, while α-BiP interacts weakly with α-bismuthene so that its semiconducting property is preserved. The study demonstrates an attractive avenue for the atomic-scale growth of binary 2D materials via substrate phase engineering.

Analysis of Strain and Defects in Tellurium-WSe2 Moiré Heterostructures Using Scanning Nanodiffraction

In recent years, there has been an increasing focus on 2D nongraphene materials that range from insulators to semiconductors to metals. As a single-elemental van der Waals semiconductor, tellurium (Te) has captivating anisotropic physical properties. Recent work demonstrated growth of ultrathin Te on WSe2 with the atomic chains of Te aligned with the armchair directions of the substrate using physical vapor deposition (PVD). In this system, a moiré superlattice is formed where micrometer-scale Te flakes sit on top of the continuous WSe2 film. Here, we determined the precise orientation of the Te flakes with respect to the substrate and detailed structure of the resulting moiré lattice by combining electron microscopy with image simulations. We directly visualized the moiré lattice using center of mass-differential phase contrast (CoM-DPC). We also investigated the local strain within the Te/WSe2 layered materials using scanning nanodiffraction techniques. There is a significant tensile strain at the edges of flakes along the direction perpendicular to the Te chain direction, which is an indication of the preferred orientation for the growth of Te on WSe2. In addition, we observed local strain relaxation regions within the Te film, specifically attributed to misfit dislocations, which we characterize as having a screw-like nature. The detailed structural analysis gives insight into the growth mechanisms and strain relaxation in this moiré heterostructure.

Phase Engineering of 2D Spinel-Type Manganese Oxides

2D magnetic materials have been of interest due to their unique long-range magnetic ordering in the low-dimensional regime and potential applications in spintronics. Currently, most studies are focused on strippable van der Waals magnetic materials with layered structures, which typically suffer from a poor stability and scarce species. Spinel oxides have a good environmental stability and rich magnetic properties. However, the isotropic bonding and close-packed nonlayered crystal structure make their 2D growth challenging, let alone the phase engineering. Herein, a phase-controllable synthesis of 2D single-crystalline spinel-type oxides is reported. Using the van der Waals epitaxy strategy, the thicknesses of the obtained tetragonal and hexagonal manganese oxide (Mn3 O4 ) nanosheets can be tuned down to 7.1 nm and one unit cell (0.7 nm), respectively. The magnetic properties of these two phases are evaluated using vibrating-sample magnetometry and first-principle calculations. Both structures exhibit a Curie temperature of 48 K. Owing to its ultrathin geometry, the Mn3 O4 nanosheet exhibits a superior ultraviolet detection performance with an ultralow noise power density of 0.126 pA Hz-1/2 . This study broadens the range of 2D magnetic semiconductors and highlights their potential applications in future information devices.

Broadband SnS/Te photodetector to long-wavelength infrared: breaking the spectrum limit through alloy engineering

Materials based on group IV chalcogenides, are considered to be one of the most promising materials for high-performance, broadband photodetectors due to their wide bandgap coverage, intriguing chemical bonding and excellent physical properties. However, the reported photodetectors based on SnS are still worked at relatively narrow near-infrared band (as far as 1550 nm) hampered by the nonnegligible bandgap of 1.1-1.5 eV. Here, a novel photodetector based on Te alloyed SnS thin film was demonstrated with an ultra-broadband response up to 10.6 µm. By controlling the Te alloyed concentration in SnS increasing to 37.64%, the bandgap narrows to 0.23 eV, exhibiting a photoresponse potential at long-wavelength infrared excitation. Our results show Te-alloying can remarkably enhance the detection properties of SnS/Te photodetectors. The photoresponsivity and detectivity of 1.59 mA/W and 2.3 × 108 Jones were realized at 10.6 µm at room temperature. Moreover, the nonzero photogain was observed generated by nonlinearly increased photocurrent density, resulting in a superlinear dependency between photoresponsivity and light intensity. Our studies successfully broaden photoresponse spectrum of SnS toward the mid-infrared range for the first time. It also suggests that alloying is an effective technique for tuning the band edges of group IV chalcogenides, contributing deep implications for developing future optoelectronic applications.

Atomic Layer Deposition Route to Scalable, Electronic-Grade van der Waals Te Thin Films

Scalable production and integration techniques for van der Waals (vdW) layered materials are vital for their implementation in next-generation nanoelectronics. Among available approaches, perhaps the most well-received is atomic layer deposition (ALD) due to its self-limiting layer-by-layer growth mode. However, ALD-grown vdW materials generally require high processing temperatures and/or additional postdeposition annealing steps for crystallization. Also, the collection of ALD-producible vdW materials is rather limited by the lack of a material-specific tailored process design. Here, we report the annealing-free wafer-scale growth of monoelemental vdW tellurium (Te) thin films using a rationally designed ALD process at temperatures as low as 50 °C. They exhibit exceptional homogeneity/crystallinity, precise layer controllability, and 100% step coverage, all of which are enabled by introducing a dual-function co-reactant and adopting a so-called repeating dosing technique. Electronically, vdW-coupled and mixed-dimensional vertical p-n heterojunctions with MoS2 and n-Si, respectively, are demonstrated with well-defined current rectification as well as spatial uniformity. Additionally, we showcase an ALD-Te-based threshold switching selector with fast switching time (∼40 ns), selectivity (∼104), and low Vth (∼1.3 V). This synthetic strategy allows the low-thermal-budget production of vdW semiconducting materials in a scalable fashion, thereby providing a promising approach for monolithic integration into arbitrary 3D device architectures.

Renaissance of elemental phosphorus materials: properties, synthesis, and applications in sustainable energy and environment

The polymorphism of phosphorus-based materials has garnered much research interest, and the variable chemical bonding structures give rise to a variety of micro and nanostructures. Among the different types of materials containing phosphorus, elemental phosphorus materials (EPMs) constitute the foundation for the synthesis of related compounds. EPMs are experiencing a renaissance in the post-graphene era, thanks to recent advancements in the scaling-down of black phosphorus, amorphous red phosphorus, violet phosphorus, and fibrous phosphorus and consequently, diverse classes of low-dimensional sheets, ribbons, and dots of EPMs with intriguing properties have been produced. The nanostructured EPMs featuring tunable bandgaps, moderate carrier mobility, and excellent optical absorption have shown great potential in energy conversion, energy storage, and environmental remediation. It is thus important to have a good understanding of the differences and interrelationships among diverse EPMs, their intrinsic physical and chemical properties, the synthesis of specific structures, and the selection of suitable nanostructures of EPMs for particular applications. In this comprehensive review, we aim to provide an in-depth analysis and discussion of the fundamental physicochemical properties, synthesis, and applications of EPMs in the areas of energy conversion, energy storage, and environmental remediation. Our evaluations are based on recent literature on well-established phosphorus allotropes and theoretical predictions of new EPMs. The objective of this review is to enhance our comprehension of the characteristics of EPMs, keep abreast of recent advances, and provide guidance for future research of EPMs in the fields of chemistry and materials science.

High Performance GaN-Based Ultraviolet Photodetector via Te/Metal Electrodes

Photodetectors (PDs) based on two-dimensional (2D) materials have promising applications in modern electronics and optoelectronics. However, due to the intralayer recombination of the photogenerated carriers and the inevitable surface trapping stages of the constituent layers, the PDs based on 2D materials usually suffer from low responsivity and poor response speed. In this work, a distinguished GaN-based photodetector is constructed on a sapphire substrate with Te/metal electrodes. Due to the metal-like properties of tellurium, the band bending at the interface between Te and GaN generates an inherent electric field, which greatly reduces the carrier transport barrier and promotes the photoresponse of GaN. This Te-enhanced GaN-based PD show a promising responsivity of 4951 mA/W, detectivity of 1.79 × 10¹⁴ Jones, and an external quantum efficiency of 169%. In addition, owing to the collection efficiency of carriers by this Te-GaN interface, the response time is greatly decreased compared with pure GaN PDs. This high performance can be attributed to the fact that Te reduces the contact resistance of the metal electrode Au/Ti to GaN, forming an ohmic-like contact and promoting the photoresponse of GaN. This work greatly extends the application potential of GaN in the field of high-performance photodetectors and puts forward a new way of developing high performance photodetectors.

Formation Mechanism of Elemental Te Produced in Tellurite Glass Systems by Femtosecond Laser Irradiation

The formation of elemental trigonal tellurium (t-Te) on tellurite glass surfaces exposed to femtosecond laser pulses is discussed. Specifically, the underlying elemental crystallization phenomenon is investigated by altering laser parameters in common tellurite glass compositions under various ambient conditions. Elemental crystallization of t-Te by a single femtosecond laser pulse is unveiled by high-resolution imaging and analysis. The thermal diffusion model reveals the absence of lattice melting upon a single laser pulse, highlighting the complexity of the phase transformation. The typical cross-section displays three different crystal configurations over its depth, in which the overall thickness increases with each subsequent pulse. The effect of various controlled atmospheres shows the suppressing nature of the elemental crystallization, whereas the substrate temperature shows no significant impact on the nucleation of t-Te nanocrystals. This research gives new insight into the elemental crystallization of glass upon femtosecond laser irradiation and shows the potential to fabricate functional transparent electronic micro/nanodevices.

Rectangular-Phase Tellurene on Ni(111) from Monolayer Films to Periodic Striped Patterns

As an emerging member of monoelemental two-dimensional (2D) materials, 2D tellurium (tellurene) has recently attracted intensive attention due to its polymorphism arising from the multivalent nature and fascinating properties such as wide-range band gaps, high carrier mobilities, etc. Herein, we predict the formation of a rectangular-phase tellurene on Ni(111) by first-principles density functional theory (DFT) calculations and realize its direct syntheses and characterizations by molecular beam epitaxy (MBE) and scanning tunneling microscopy (STM). We reveal that the monolayer rectangular tellurene and underlying Ni(111) substrate are strongly coupled, along with good lattice registry along two mutually perpendicular directions, which serves as the key driving force for the tellurene formation. We also uncover the unique morphological transitions of Te/Ni(111) from rectangular tellurene monolayer, to uniform periodic striped patterns at the second layer, and then to thick striped patterns. This work should offer valuable insights for the substrate-mediated syntheses of monoelemental 2D materials, thus propelling their phase engineering and intriguing property explorations.

Molecular beam epitaxy growth and scanning tunneling microscopy study of 2D layered materials on epitaxial graphene/silicon carbide

Since the advent of atomically flat graphene, two-dimensional (2D) layered materials have gained extensive interest due to their unique properties. The 2D layered materials prepared on epitaxial graphene/silicon carbide (EG/SiC) surface by molecular beam epitaxy (MBE) have high quality, which can be directly applied without further transfer to other substrates. Scanning tunneling microscopy and spectroscopy (STM/STS) with high spatial resolution and high-energy resolution are often used to study the morphologies and electronic structures of 2D layered materials. In this review, recent progress in the preparation of various 2D layered materials that are either monoelemental or transition metal dichalcogenides on EG/SiC surface by MBE and their STM/STS investigations are introduced.

Solution-processed thickness engineering of tellurene for field-effect transistors and polarized infrared photodetectors

Research on elemental 2D materials has been experiencing a renaissance in the past few years. Of particular interest is tellurium (Te), which possesses many exceptional properties for nanoelectronics, photonics, and beyond. Nevertheless, the lack of a scalable approach for the thickness engineering and the local properties modulation remains a major obstacle to unleashing its full device potential. Herein, a solution-processed oxidative etching strategy for post-growth thickness engineering is proposed by leveraging the moderate chemical reactivity of Te. Large-area ultrathin nanosheets with well-preserved morphologies could be readily obtained with appropriate oxidizing agents, such as HNO2, H2O2, and KMnO4. Compared with the conventional physical thinning approaches, this method exhibits critical merits of high efficiency, easy scalability, and the capability of site-specific thickness patterning. The thickness reduction leads to substantially improved gate tunability of field-effect transistors with an enhanced current switching ratio of ∼103, promoting the applications of Te in future logic electronics. The response spectrum of Te phototransistors covers the full range of short-wave infrared wavelength (1-3 μm), and the room-temperature responsivity and detectivity reach 0.96 AW-1 and 2.2 × 109 Jones at the telecom wavelength of 1.55 μm, together with a favorable photocurrent anisotropic ratio of ∼2.9. Our study offers a new approach to tackling the thickness engineering issue for solution-grown Te, which could help realize the full device potential of this emerging p-type 2D material.

Giant in-plane optical and electronic anisotropy of tellurene: a quantitative exploration

Tellurene's giant in-plane optical anisotropy brings richer physics and an extra degree of freedom to regulate its optical properties for designing novel and unique polarization-sensitive devices. Here, we quantitatively evaluate the in-plane optical anisotropy of tellurene and further reveal its physical origins by combining imaging Mueller matrix spectroscopic ellipsometry (MMSE) and first-principles calculations. The anisotropic complex refractive indices and dielectric functions, as well as the derived giant birefringence (|Δn|_max = 0.48) and dichroism (Δk > 0.4), are accurately determined by imaging MMSE to quantitatively evaluate the in-plane optical anisotropy of tellurene. With density functional theory (DFT), tellurene's optical anisotropy is connected to its low-symmetry lattice structure with electrical anisotropy (including the anisotropic effective mass, partial charge density, and carrier mobility), leading to anisotropic electric polarization and ultimately optical anisotropy. This work provides a general and quantitative way to explore the optical anisotropy and also helps to comprehend the connection between the lattice structure and the optical anisotropy of tellurene and even other emerging low-symmetry materials, which will further promote their polarization-sensitive optical applications.

All-van-der-Waals Barrier-Free Contacts for High-Mobility Transistors

Ultrathin 2D semiconductor devices are considered to have beyond-silicon potential but are severely troubled by the high Schottky barriers of the metal-semiconductor contacts, especially for p-type semiconductors. Due to the severe Fermi-level pinning effect and the lack of conventional semimetals with high work functions, their Schottky hole barriers are hardly removed. Here, an all-van-der-Waals barrier-free hole contact between p-type tellurene semiconductor and layered 1T'-WS₂ semimetal is reported, which achieves a zero Schottky barrier height of 3 ± 9 meV and a high field-effect mobility of ≈1304 cm² V^-1 s^-1 . The formation of such contacts can be attributed to the higher work function of ≈4.95 eV of the 1T'-WS₂ semimetal, which is in sharp contrast with low work function (4.1-4.7 eV) of conventional semimetals. The study defines an available strategy for eliminating the Schottky barrier of metal-semiconductor contacts, facilitating 2D-semiconductor-based electronics and optoelectronics to extend Moore's law.

Geometry of tellurene adsorbed on the Si(111)-R30°-Sb surface from first principles calculations

The 2D form of tellurium, named tellurene, is one of the latest discoveries in the family of 2D mono-elemental materials. In a trilayer configuration, free-standing tellurene was predicted theoretically to acquire two crystallographic forms, the α and β phases, corresponding to either a 1T-MoS₂-like geometry or a trilayer slab exposing the Te(101̄0) surface of bulk Te with helical chains lying in-plane and further reconstructed due to the formation of interchain bonds. Either one or the other of the two phases was observed experimentally to prevail depending on the substrate they were grown onto. In the perspective to integrate tellurene on silicon, we here report an ab initio study of the adsorption of tellurene on the Si(111)-R30° surface passivated by antinomy. According to the literature, this substrate is chosen for the growth of several tellurides by molecular beam epitaxy. The calculations reveal that on this substrate the adsorption energy mostly compensates the energy difference between the α and β phases in the free-standing configuration which suggests that the prevalence of one phase over the other might in this case strongly depend on the kinetics effects and deposition conditions.

Evolution of the Electronic and Optical Properties of Meta-Stable Allotropic Forms of 2D Tellurium for Increasing Number of Layers

In this work, ab initio Density Functional Theory calculations are performed to investigate the evolution of the electronic and optical properties of 2D Tellurium-called Tellurene-for three different allotropic forms (α-, β- and γ-phase), as a function of the number of layers. We estimate the exciton binding energies and radii of the studied systems, using a 2D analytical model. Our results point out that these quantities are strongly dependent on the allotropic form, as well as on the number of layers. Remarkably, we show that the adopted method is suitable for reliably predicting, also in the case of Tellurene, the exciton binding energy, without the need of computationally demanding calculations, possibly suggesting interesting insights into the features of the system. Finally, we inspect the nature of the mechanisms ruling the interaction of neighbouring Tellurium atoms helical chains (characteristic of the bulk and α-phase crystal structures). We show that the interaction between helical chains is strong and cannot be explained by solely considering the van der Waals interaction.

Single-Element 2D Materials beyond Graphene: Methods of Epitaxial Synthesis

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.

Elemental Two-Dimensional Materials for Li/Na-Ion Battery Anode Applications

Two-dimensional (2D) nanostructure is currently the subject in the fields of new energy storage and devices. During the past years, a broad range of 2D materials represented by graphene have been developed and endow with excellent electrochemical properties. Among them, elemental 2D materials (Xenes) are an emerged material family for Li/Na-ion battery (LIB/SIB) anodes. Compared with other 2D materials and bulk materials, Xenes may exhibit some great superiorities for Li/Na storage, including excellent conductivity, fast ion diffusion and large active sites exposure. In this review, we provide a systematic summary of the recent progress and achievements of Xenes as well as their applications in LIBs/SIBs. The broad categorization of Xenes from group IIIA to VIA has been concisely outlined, and the related details in syntheses, structures and Li/Na-ion storage properties are reviewed. Further, the latest research progress of Xenes in Li/Na ion batteries are summarized, together with mechanism discussions. Finally, the challenges and prospects of Xenes applied to Li/Na ion battery are proposed based on its current developments.

Tellurium based materials for nonlinear optical applications

Materials having broadband nonlinear optical responses find applications in photonics and optoelectronics devices. Novel materials with improved nonlinear optical properties are necessary for realizing effective all-optical switches, modulators etc. Tellurium (Te) and novel low-dimensional derivatives of Te offer intriguing nonlinear optical responses, making them promising candidates for design of various photonic devices.

Performance Limit of Ultrathin GaAs Transistors

High-electron-mobility group III-V compounds have been regarded as a promising successor to silicon in next-generation field-effect transistors (FETs). Gallium arsenide (GaAs) is an outstanding member of the III-V family due to its advantage of both good n- and p-type device performance. Monolayer (ML) GaAs is the limit form of ultrathin GaAs. Here, a hydrogenated ML GaAs (GaAsH2) FET is simulated by ab initio quantum-transport methods. The n- and p-type ML GaAsH2 metal-oxide-semiconductor FETs (MOSFETs) can well satisfy the on-state current, delay time, power dissipation, and energy-delay product requirements of the International Technology Roadmap for Semiconductors until the gate length is scaled down to 3/4 and 3/5 nm for the high-performance/low-power applications, respectively. Therefore, ultrathin GaAs is a prominent channel candidate for devices in the post-Moore era. The p-type ML GaAsH2 MOSFETs with a 2% uniaxially compressive strain and the unstrained n-type counterparts have symmetrical performance for the high-performance application, making ultrathin GaAs applicable for complementary MOS integrated circuits.

Two-Dimensional Field-Effect Transistor Sensors: The Road toward Commercialization

The evolutionary success in information technology has been sustained by the rapid growth of sensor technology. Recently, advances in sensor technology have promoted the ambitious requirement to build intelligent systems that can be controlled by external stimuli along with independent operation, adaptivity, and low energy expenditure. Among various sensing techniques, field-effect transistors (FETs) with channels made of two-dimensional (2D) materials attract increasing attention for advantages such as label-free detection, fast response, easy operation, and capability of integration. With atomic thickness, 2D materials restrict the carrier flow within the material surface and expose it directly to the external environment, leading to efficient signal acquisition and conversion. This review summarizes the latest advances of 2D-materials-based FET (2D FET) sensors in a comprehensive manner that contains the material, operating principles, fabrication technologies, proof-of-concept applications, and prototypes. First, a brief description of the background and fundamentals is provided. The subsequent contents summarize physical, chemical, and biological 2D FET sensors and their applications. Then, we highlight the challenges of their commercialization and discuss corresponding solution techniques. The following section presents a systematic survey of recent progress in developing commercial prototypes. Lastly, we summarize the long-standing efforts and prospective future development of 2D FET-based sensing systems toward commercialization.

Formation of stable polonium monolayers with tunable semiconducting properties driven by strong quantum size effects

Elemental two-dimensional (2D) materials have attracted extraordinary interest compared with other 2D materials over the past few years. Fifteen elements from group IIIA to VIA have been discussed experimentally or theoretically for the formation of 2D monolayers, and the remaining few elements still need to be identified. Here, using first-principles calculations within density functional theory (DFT) and ab initio molecular dynamics simulations (AIMDs), we demonstrated that polonium can form stable 2D monolayers (MLs) with a 1T-MoS₂-like structure. The band structure calculations revealed that polonium monolayers possess strong semiconducting properties with a band gap of ∼0.9 eV, and such semiconducting properties can well sustain up to a thickness of 4 MLs with a bandgap of ∼0.1 eV. We also found that polonium monolayers can be achieved through a spontaneous phase transition of ultrathin films with magic thicknesses, resulting in a weaker van der Waals interaction of ∼32 meV Å^-2 between each three atomic layers. Also, the underlying physics comes from layered Peierls-like distortion driven by strong quantum size effects. Based on these intriguing findings, a suitable substrate on which the polonium monolayer can be grown through an epitaxial growth technique is proposed for further experiments. Our work not only extends completely the puzzle of elemental 2D monolayer materials from group IIIA to VIA, but also presents a new formation mechanism of 2D materials beyond the database of bulk materials with layered van der Waals interactions.

Stability, optoelectronic and thermal properties of two-dimensional Janusα-Te2S

Motivated by recent progress in the two-dimensional (2D) materials of group VI elements and their experimental fabrication, we have investigated the stability, optoelectronic and thermal properties of Janusα-Te₂S monolayer using first-principles calculations. The phonon dispersion and MD simulations confirm its dynamical and thermal stability. The moderate band gap (∼1.5 eV), ultrahigh carrier mobility (∼10³cm²V^-1s^-1), small exciton binding energy (0.26 eV), broad optical absorption range and charge carrier separation ability due to potential difference (ΔV = 1.07 eV) on two surfaces of Janusα-Te₂S monolayer makes it a promising candidate for solar energy conversion. We propose various type-II heterostructures consisting of Janusα-Te₂S and other transition metal dichalcogenides for solar cell applications. The calculated power conversion efficiencies of the proposed heterostructures, i.e.α-Te₂S/T-PdS₂,α-Te₂S/BP andα-Te₂S/H-MoS₂are ∼21%, ∼19% and 18%, respectively. Also, the ultralow value of lattice thermal conductivity (1.16 W m^-1K^-1) of Janusα-Te₂S makes it a promising material for the fabrication of next-generation thermal energy conversion devices.

Controllable synthesis of high-quality two-dimensional tellurium by a facile chemical vapor transport strategy

Recently, as an elementary material, tellurium (Te) has received widespread attention for its high carrier mobility, intriguing topological properties, and excellent environmental stability. However, it is difficult to obtain two-dimensional (2D) Te with high crystalline quality owing to its intrinsic helical chain structure. Herein, a facile strategy for controllable synthesis of high-quality 2D Te nanoflakes through chemical vapor transport in one step is reported. With carefully tuning the growth kinetics determined mainly by temperature, tellurium nanoflakes in lateral size of up to ∼40 μm with high crystallinity can be achieved. We also investigated the second harmonic generation of Te nanoflakes, which demonstrates that it can be used as frequency doubling crystals and has potential applications in nonlinear optical devices. In addition, field effect transistor devices based on the 2D Te nanoflakes were fabricated and exhibited excellent electrical properties with high mobility of 379 cm² V⁻¹ s⁻¹.

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High-quality 2D Te nanoflakes were directly synthesized by CVT method

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The growth mechanisms of 2D Te nanoflakes were systematically studied

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2D Te nanoflakes have potential applications in nonlinear optical devices

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2D Te nanoflakes-based FETs exhibit high mobility of ∼379 cm² V⁻¹ s⁻¹

Wafer-scale single-orientation 2D layers by atomic edge-guided epitaxial growth

Two-dimensional (2D) layered materials hold tremendous promise for post-Si nanoelectronics due to their unique optical and electrical properties. Significant advances have been achieved in device fabrication and synthesis routes for 2D nanoelectronics over the past decade; however, one major bottleneck preventing their immediate applications has been the lack of a reproducible approach for growing wafer-scale single-crystal films despite tremendous progress in recent experimental demonstrations. In this tutorial review, we provide a systematic summary of the critical factors-including crystal/substrate symmetry and energy consideration-necessary for synthesizing single-orientation 2D layers. In particular, we focus on the discussions of the atomic edge-guided epitaxial growth, which assists in unidirectional nucleation for the wafer-scale growth of single-crystal 2D layers.

Ultrahigh thermoelectric performance of Janus α-STe2 and α-SeTe2 monolayers

Janus α-STe2 and α-SeTe2 monolayers are investigated systematically using first-principles calculations combined with semiclassical Boltzmann transport theory.

Air-Stable 2D Cr5 Te8 Nanosheets with Thickness-Tunable Ferromagnetism

2D magnetic materials have aroused widespread research interest owing to their promising application in spintronic devices. However, exploring new kinds of 2D magnetic materials with better stability and realizing their batch synthesis remain challenging. Herein, the synthesis of air-stable 2D Cr₅ Te₈ ultrathin crystals with tunable thickness via tube-in-tube chemical vapor deposition (CVD) growth technology is reported. The importance of tube-in-tube CVD growth, which can significantly suppress the equilibrium shift to the decomposition direction and facilitate that to the synthesis reaction direction, for the synthesis of high-quality Cr₅ Te₈ with accurate composition, is highlighted. By precisely adjusting the growth temperature, the thickness of Cr₅ Te₈ nanosheets is tuned from ≈1.2 nm to tens of nanometers, with the morphology changing from triangles to hexagons. Furthermore, magneto-optical Kerr effect measurements reveal that the Cr₅ Te₈ nanosheet is ferromagnetic with strong out-of-plane spin polarization. The Curie temperature exhibits a monotonic increase from 100 to 160 K as the Cr₅ Te₈ thickness increases from 10 to 30 nm and no apparent variation in surface roughness or magnetic properties after months of exposure to air. This study provides a robust method for the controllable synthesis of high-quality 2D ferromagnetic materials, which will facilitate research progress in spintronics.

Elemental electrical switch enabling phase segregation-free operation

[Figure: see text].

Functionalized tellurene; a candidate large-gap 2D topological insulator

The discovery of group IV and V elemental xene's with topologically non-trivial characters in their honeycomb lattice structure (HLS) has led to extensive efforts in realising analogous behaviour in group VI elemental monolayers. Theoretically; it was concluded that, group VI elemental monolayers cannot exist in HLS. However, some recent experimental evidence suggests that group VI elemental monolayers can be realised in HLS. In this letter, we report HLS of group VI elemental monolayer (such as, tellurene) can be realised to be dynamically stable when functionzalised with oxygen. The functionalization leads to, peculiar orbital filtering effects and broken spatial inversion symmetry which gives rise to the non-trivial topological character. The exotic quantum behaviour of this system is characterized by, spin-orbit coupling induced large-gap (≈0.36 eV) with isolated Dirac cone along the edges indicating potential room temperature spin-transport applications. Further investigations of spin Hall conductivity and the Berry curvatures unravel high conductivity as compared to previously explored xene's alongside the potential valley Hall effects. The non-trivial topological character is quantified in terms of theZ2invariant asν= 1 and Chern numberC= 1. Also, for practical purposes, we report that,hBN/TeO/hBN quantum-wells can be strain engineered to realize a sizeable non-trivial gap (≈0.11 eV). We finally conclude that, functionalization of group VI elemental monolayer with oxygen gives rise to, exotic quantum properties which are robust against surface oxidation and degradations while providing viable electronic degrees of freedom for spintronic/valleytronic applications.

Chemistry, Functionalization, and Applications of Recent Monoelemental Two-Dimensional Materials and Their Heterostructures

The past decades have witnessed a rapid expansion in investigations of two-dimensional (2D) monoelemental materials (Xenes), which are promising materials in various fields, including applications in optoelectronic devices, biomedicine, catalysis, and energy storage. Apart from graphene and phosphorene, recently emerging 2D Xenes, specifically graphdiyne, borophene, arsenene, antimonene, bismuthene, and tellurene, have attracted considerable interest due to their unique optical, electrical, and catalytic properties, endowing them a broader range of intriguing applications. In this review, the structures and properties of these emerging Xenes are summarized based on theoretical and experimental results. The synthetic approaches for their fabrication, mainly bottom-up and top-down, are presented. Surface modification strategies are also shown. The wide applications of these emerging Xenes in nonlinear optical devices, optoelectronics, catalysis, biomedicine, and energy application are further discussed. Finally, this review concludes with an assessment of the current status, a description of existing scientific and application challenges, and a discussion of possible directions to advance this fertile field.

Bonding, structure, and mechanical stability of 2D materials: the predictive power of the periodic table

This tutorial review describes the ongoing effort to convert main-group elements of the periodic table and their combinations into stable 2D materials, which is sometimes called modern 'alchemy'. Theory is successfully approaching this goal, whereas experimental verification is lagging far behind in the synergistic interplay between theory and experiment. The data collected here gives a clear picture of the bonding, structure, and mechanical performance of the main-group elements and their binary compounds. This ranges from group II elements, with two valence electrons, to group VI elements with six valence electrons, which form not only 1D structures but also, owing to their variable oxidation states, low-symmetry 2D networks. Outside of these main groups reviewed here, predominantly ionic bonding may be observed, for example in group II-VII compounds. Besides high-symmetry graphene with its shortest and strongest bonds and outstanding mechanical properties, low-symmetry 2D structures such as various borophene and tellurene phases with intriguing properties are receiving increasing attention. The comprehensive discussion of data also includes bonding and structure of few-layer assemblies, because the electronic properties, e.g., the band gap, of these heterostructures vary with interlayer layer separation and interaction energy. The available data allows the identification of general relationships between bonding, structure, and mechanical stability. This enables the extraction of periodic trends and fundamental rules governing the 2D world, which help to clear up deviating results and to estimate unknown properties. For example, the observed change of the bond length by a factor of two alters the cohesive energy by a factor of four and the extremely sensitive Young's modulus and ultimate strength by more than a factor of 60. Since the stiffness and strength decrease with increasing atom size on going down the columns of the periodic table, it is important to look for suitable allotropes of elements and binaries in the upper rows of the periodic table when mechanical stability and robustness are issues. On the other hand, the heavy compounds are of particular interest because of their low-symmetry structures with exotic electronic properties.

Emerging beyond-graphene elemental 2D materials for energy and catalysis applications

Elemental two-dimensional (2D) materials have emerged as promising candidates for energy and catalysis applications due to their unique physical, chemical, and electronic properties. These materials are advantageous in offering massive surface-to-volume ratios, favorable transport properties, intriguing physicochemical properties, and confinement effects resulting from the 2D ultrathin structure. In this review, we focus on the recent advances in emerging energy and catalysis applications based on beyond-graphene elemental 2D materials. First, we briefly introduce the general classification, structure, and properties of elemental 2D materials and the new advances in material preparation. We then discuss various applications in energy harvesting and storage, including solar cells, piezoelectric and triboelectric nanogenerators, thermoelectric devices, batteries, and supercapacitors. We further discuss the explorations of beyond-graphene elemental 2D materials for electrocatalysis, photocatalysis, and heterogeneous catalysis. Finally, the challenges and perspectives for the future development of elemental 2D materials in energy and catalysis are discussed.

Prediction of allotropes of tellurium with molecular, one- and two-dimensional covalent nets for photofunctional applications

In the present work, three new semiconducting two-dimensional (2D) Te phases containing three- and four-coordinated Te centers were proposed by using evolutionary algorithms combined with first-principles calculations. Using density functional theory calculations, we discussed the bonding and electronic properties in these phases, and subsequently rationalized their structures. The viability of these predicted structures was demonstrated by evaluating their thermodynamic, dynamic, mechanical, and thermal stabilities. Moreover, a significant direct band gap (0.951-1.512 eV) and excellent transport properties were evidenced in 2D Te nets, which suggests that they could be promising photovoltaic materials candidates. This is further supported by the stability of the associated bulk layered counterparts of the 2D Te nets.

Schottky barrier heights in two-dimensional field-effect transistors: from theory to experiment

Over the past decade, two-dimensional semiconductors (2DSCs) have aroused wide interest due to their extraordinary electronic, magnetic, optical, mechanical, and thermal properties, which hold potential in electronic, optoelectronic, thermoelectric applications, and so forth. The field-effect transistor (FET), a semiconductor gated with at least three terminals, is pervasively exploited as the device geometry for these applications. For lack of effective and stable substitutional doping techniques, direct metal contact is often used in 2DSC FETs to inject carriers. A Schottky barrier (SB) generally exists in the metal-2DSC junction, which significantly affects and even dominates the performance of most 2DSC FETs. Therefore, low SB or Ohmic contact is highly preferred for approaching the intrinsic characteristics of the 2DSC channel. In this review, we systematically introduce the recent progress made in theoretical prediction of the SB height (SBH) in the 2DSC FETs and the efforts made both in theory and experiments to achieve low SB contacts. From the comparison between the theoretical and experimentally observed SBHs, the emerging first-principles quantum transport simulation turns out to be the most powerful theoretical tool to calculate the SBH of a 2DSC FET. Finally, we conclude this review from the viewpoints of state-of-the-art electrode designs for 2DSC FETs.

Recent progress, challenges, and prospects in emerging group-VIA Xenes: synthesis, properties and novel applications

The discovery of graphene (G) attracted considerable attention to the study of other novel two-dimensional materials (2DMs), which is identified as modern day "alchemy" since researchers are converting the majority of promising periodic table elements into 2DMs. Among the family of 2DMs, the newly invented monoelemental, atomically thin 2DMs of groups IIIA-VIA, called "Xenes" (where, X = IIIA-VIA group elements, and "ene" is the Latin word for nanosheets (NSs)), are a very active area of research for the fabrication of future nanodevices with high speed, low cost and elevated efficiency. Currently, any novel structure of 2DMs from the typical Xenes will probably be applicable in electronic technology. Analysis of their possible highly sensitive synthesis and characterization present opportunities for theoretically examining proposed 2D-Xenes with atomic precision in ideal circumstances, thus providing theoretical predictions for experimental support. Several theoretically predicted and experimentally synthesized 2D-Xene materials have been investigated for the group-VIA elements (tellurene (2D-Te), and selenene (2D-Se)), which are similar to topological insulators (TIs), thus potentially rendering them suitable materials for application in upcoming nanodevices. Although the investigation and device application of these materials are still in their infancy, theoretical studies and a few experiment-based investigations have proven that they are complementary to conventional (i.e., layered bulk-derived) 2DMs. This review focuses on the synthesis of novel group-VIA Xenes (2D-Te and 2D-Se) and summarizes the current development in understanding their basic properties, with the current advancement in signifying device applications. Lastly, the future research prospects, further advanced applications and associated shortcomings of the group-VIA Xenes are summarized and highlighted.

Tellurium Nanowire Gate-All-Around MOSFETs for Sub-5 nm Applications

The nanowire (NW) and gate-all-around (GAA) technologies are regarded as the ultimate solutions to sustain Moore's law benefitting from the exceptional gate control ability. Herein, we conduct a comprehensive ab initio quantum transportation calculation at different diameters (single trigonal-tellurium NW (1Te) and three trigonal-tellrium NW (3Te)) sub-5 nm tellurium (Te) GAA NW metal-oxide-semiconductor field-effect transistors (MOSFETs). The results claim that the performance of 1Te FETs is superior to that of 3Te FETs. Encouragingly, the single Te (1Te) n-type MOSFET with 5 nm gate length achieves International Technology Roadmap for Semiconductors (ITRS) high-performance (HP) and low-dissipation (LP) goals simultaneously. Especially, the HP on-state current reaches 6479 μA/μm, 7 times higher than the goal (900 μA/μm). Moreover, the subthreshold swing of the n-type 1Te FETs even hits a thermionic limit of 60 mV/dec. In terms of the spin-orbit coupling effect, the drain currents of devices are further improved, particularly the p-type Te FETs can also achieve the ITRS HP goal. Hence, the GAA Te MOSFETs provide a feasible approach for state-of-the-art sub-5 nm device applications.