Singh Jaspreet, Jamdagni Pooja, Jakhar Mukesh, Kumar Ashok
Department of Physical Sciences, School of Basic and Applied Sciences, Central University of Punjab, Bathinda, 151001, India.
Department of Physics, Himachal Pradesh University, Shimla, Himachal Pradesh 171005, India.
Phys Chem Chem Phys. 2020 Mar 14;22(10):5749-5755. doi: 10.1039/d0cp00511h. Epub 2020 Feb 27.
The successful experimental fabrication of 2D tellurium (Te) has resulted in growing interest in the monolayers of group VI elements. By employing density functional theory, we have explored the stability and electronic and mechanical properties of 1T-MoS-like chalcogen (α-Se and α-Te) monolayers. Phonon spectra are free from imaginary modes suggesting these monolayers to be dynamically stable. The stability of these monolayers is further confirmed by room temperature AIMD simulations. Both α-Se and α-Te are indirect gap semiconductors with a band gap (calculated using the hybrid HSE06 functional) of 1.16 eV and 1.11 eV, respectively, and these gaps are further tunable with mechanical strains. Both monolayers possess strong absorption spectra in the visible region. The ideal strengths of these monolayers are comparable with those of many existing 2D materials. Significantly, these monolayers possess ultrahigh carrier mobilities of the order of 10 cm V s. Combining the semiconducting nature, visible light absorption and superior carrier mobilities, these monolayers can be promising candidates for the superior performance of next-generation nanoscale devices.
二维碲（Te）的成功实验制备引发了人们对第VI族元素单层材料的兴趣不断增加。通过运用密度泛函理论，我们研究了类1T-MoS硫族元素（α-硒和α-碲）单层的稳定性、电学和力学性质。声子谱没有虚模，表明这些单层在动力学上是稳定的。室温下的从头算分子动力学模拟进一步证实了这些单层的稳定性。α-硒和α-碲均为间接带隙半导体，其带隙（使用杂化HSE06泛函计算）分别为1.16 eV和1.11 eV，并且这些带隙可通过机械应变进一步调节。两种单层在可见光区域都具有很强的吸收光谱。这些单层的理想强度与许多现有二维材料相当。值得注意的是，这些单层具有高达10 cm² V⁻¹ s⁻¹的超高载流子迁移率。结合半导体性质、可见光吸收和优异的载流子迁移率，这些单层有望成为下一代纳米级器件高性能的候选材料。
