Few-layer Tellurium: one-dimensional-like layered elementary semiconductor with striking physical properties

Jingsi Qiao; Yuhao Pan; Feng Yang; Cong Wang; Yang Chai; Wei Ji

doi:10.1016/j.scib.2018.01.010

Few-layer Tellurium: one-dimensional-like layered elementary semiconductor with striking physical properties

Sci Bull (Beijing). 2018 Feb 15;63(3):159-168. doi: 10.1016/j.scib.2018.01.010. Epub 2018 Jan 9.

Authors

Jingsi Qiao¹, Yuhao Pan², Feng Yang², Cong Wang², Yang Chai³, Wei Ji⁴

Affiliations

¹ Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China; Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China.
² Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China.
³ Department of Applied Physics, The Hong Kong Polytechnic University, Hong Kong, China.
⁴ Beijing Key Laboratory of Optoelectronic Functional Materials & Micro-Nano Devices, Department of Physics, Renmin University of China, Beijing 100872, China. Electronic address: wji@ruc.edu.cn.

PMID: 36659001
DOI: 10.1016/j.scib.2018.01.010

Abstract

Few-layer Tellurium, an elementary semiconductor, succeeds most of striking physical properties that black phosphorus (BP) offers and could be feasibly synthesized by simple solution-based methods. It is comprised of non-covalently bound parallel Te chains, among which covalent-like feature appears. This feature is, we believe, another demonstration of the previously found covalent-like quasi-bonding (CLQB) where wavefunction hybridization does occur. The strength of this inter-chain CLQB is comparable with that of intra-chain covalent bonding, leading to closed stability of several Te allotropes. It also introduces a tunable bandgap varying from nearly direct 0.31 eV (bulk) to indirect 1.17 eV (2L) and four (two) complex, highly anisotropic and layer-dependent hole (electron) pockets in the first Brillouin zone. It also exhibits an extraordinarily high hole mobility (∼10⁵ cm²/Vs) and strong optical absorption along the non-covalently bound direction, nearly isotropic and layer-dependent optical properties, large ideal strength over 20%, better environmental stability than BP and unusual crossover of force constants for interlayer shear and breathing modes. All these results manifest that the few-layer Te is an extraordinary-high-mobility, high optical absorption, intrinsic-anisotropy, low-cost-fabrication, tunable bandgap, better environmental stability and nearly direct bandgap semiconductor. This "one-dimension-like" few-layer Te, together with other geometrically similar layered materials, may promote the emergence of a new family of layered materials.

Keywords: Covalent-like quasi-bonding; First-principles calculations; High carrier mobility; One-dimension-like layered materials; Tellurium; Two-dimensional systems.