Tellurium: Fast Electrical and Atomic Transport along the Weak Interaction Direction

Abstract

In anisotropic materials, the electrical and atomic transport along the weak interaction direction is usually much slower than that along the chemical bond direction. However, Te, an important semiconductor composed of helical atomic chains, exhibits nearly isotropic electrical transport between intrachain and interchain directions. Using first-principles calculations to study bulk and few-layer Te, we show that this isotropy is related to similar effective masses and potentials for charge carriers along different transport directions, benefiting from the delocalization of the lone-pair electrons. This delocalization also enhances the interchain binding, and thus facilitates diffusion of vacancies and interstitial atoms across the chains, which together with the fast intrachain diffusion enable rapid self-healing of these defects at low temperature. Interestingly, the interstitial atoms diffuse along the chain via a concerted rotation mechanism. Our work reveals the unconventional properties underlying the superior performance of Te while providing insight into the transport in anisotropic materials.

Strain‐Engineered Anisotropic Optical and Electrical Properties in 2D Chiral‐Chain Tellurium

“…Tellurium (Te) hosts a unique chiral‐chain structure different from the lattices of the widely studied 2D layered materials [ 59,60 ] ( Figure a.). The helical chains, stacked through a weak interaction, [ 50,61 ] consist of covalently bonded Te atoms and exhibit a three‐fold screw symmetry along the [0001] direction. [ 62 ] The high‐resolution transmission electron microscopy (TEM) results in Figure 1b resolves such characteristic helical‐chain lattice of our solution‐grown 2D Te, which naturally exhibits geometric anisotropy with the long, straight edge always parallel to the [0001] direction [ 45,41,49 ] (Figure 1c).…”

“…[ 62 ] When the prestrain was applied along the direction, tensile, and compressive strains were induced along the direction in the crest and valley regions, respectively, of the buckled 2D Te. However, the absence of covalent bond along the direction [ 61 ] and larger space (the intrachain between neighboring Te atoms is 0.29 nm, while the interchain distance is 0.35 nm) along this direction makes the external strain to be released without significant bond and bond angle change compared to the [0001] case (see our density functional theory (DFT) calculation results in Table S2, Supporting Information). Moreover, it has been revealed by the previous literature [ 89 ] that the optical activity along [0001] direction is higher than that in the direction in tellurium.…”

Epitaxial Growth of 1D Atomic Chain Based Se Nanoplates on Monolayer ReS2 for High‐Performance Photodetectors

“…Most of the components in the reported mixed‐dimensional heterostructures are layered materials with the same planar crystal structures. However, 1D van der Waals elemental materials Se and Te could also exhibit interesting physical properties such as high photoconductivity, high piezoelectricity, thermoelectricity, and nonlinear optical responses . In trigonal Se, the Se atoms are covalently bonded along the c axis into a spiral chain, and these isolated chains could be stacked radially by weak van der Waals interactions to form a hexagonal structure.…”

Allotropes of tellurium from first-principles crystal structure prediction calculations under pressure

“…6,7 In addition, very recently, structures with few-layers of tellurium were studied as two-dimensional topological materials. 8,9 In fact, it presents topological properties for electronic transport, benetting from the nonsymmorphic screw symmetry, the lonepair electrons and the strong spin-orbit interaction. [10][11][12] For the ground-state chiral tellurium, the band splitting and band inversion were found upon the application of shear strain or pressure [13][14][15] together with the existence of topological Weyl nodes near the Fermi level.…”