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Transition state calculation is a critical technique to understand and predict versatile dynamical phenomena in solids. However, the transition state results obtained at 0 K are often utilized for the prediction or interpretation of dynamical processes at high temperatures, and the error bars of such an approximation are largely unknown. In this benchmark study, all the major temperature effects, including lattice expansion, lattice vibration, electron excitation, and band-edge shift, are evaluated with first-principles calculations for defect diffusion in solids. With the inclusion of these temperature effects, the notable discrepancies between theoretical predictions at 0 K and the experimental diffusivities at high temperatures are dramatically reduced. In particular, we find that lattice expansion and lattice vibration are the dominant factors lowering the defect formation energies and hopping barriers at high temperatures, but the electron excitation exhibits minor effects. In sharp contrast to typical assumptions, the attempt frequency with lattice expansion and vibration varies significantly with materials: several THz for aluminum bulk but surprisingly over 500 THz for 4H-SiC. For defects in semiconductors, the band-edge shift is also significant at high temperatures and plays a vital role in defect diffusion. We expect that this study would help accurately predict the dynamical processes at high temperatures. [ABSTRACT FROM AUTHOR]

The remarkable successes of graphene have sparked increasing interest in elemental two‐dimensional (2D) materials, also referred to as Xenes. Due to their chemical simplicity and appealing physiochemical properties, Xenes have shown particular potential for numerous (opto) electronic, iontronic, and energy applications. Among them, layered α‐phase tellurene has demonstrated the most promise, thanks to the recent successes in the chemical synthesis of highly crystalline 2D tellurene. However, the general electronic and electrochemical properties of tellurene in electrolyte systems remain ambiguous, hindering their further development. In this work, we studied the electrostatic gating, electrocatalysis, and electrochemical stability of tellurene in electrolyte systems. Our results show that tellurene obtained from both hydrothermal and chemical vapor deposition methods, two mainstream synthetic approaches for Xenes, demonstrates thickness‐dependent ambipolar transport with high hole mobility and stability in both aqueous electrolytes and ionic liquids. More importantly, the electrochemical properties of tellurene are investigated via the emerging on‐chip electrochemistry. Pristine tellurene demonstrates hydrogen evolution reaction with low Tafel slopes and remarkable electrochemical stability in acidic electrolytes over a large potential window. Our study provides a comprehensive understanding of the iontronic and electrochemical properties of tellurene, paving the way for the broad adoption of Xenes in sensors, synaptic devices, and electrocatalysis. [ABSTRACT FROM AUTHOR]

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'-MoTe 2 . 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 cm 2  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., (© 2023 Wiley‐VCH GmbH.)