Exfoliation energy, quasiparticle band structure, and excitonic properties of selenium and tellurium atomic chains
Exfoliation energy, quasiparticle band structure, and excitonic properties of selenium and tellurium atomic chains
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DOI：
10.1103/physrevb.98.035420
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发表时间：
2018-07-13
影响因子：
3.7
通讯作者：
Barraza-Lopez, Salvador
中科院分区：
文献类型：
--
作者：
Andharia, Eesha;Kaloni, Thaneshwor P.;Barraza-Lopez, Salvador
广义梯度密度泛函理论不能捕捉到的效应对降维弱结合材料的结构结合以及电子和光学性质有显著的影响。在这里，我们报告的剥离能量的硒和碲原子链的非经验货车德瓦尔斯修正，和他们的电子和光学性质的G-W和Bethe-Salpeter形式主义。剥离能在0.547-0.719 eV/u.c之间。对于硒原子链，为0.737-0.926 eV/u. c.对于碲原子链（其中u.c.代表晶胞），这取决于货车德瓦尔斯相互作用的近似和所选择的数值工具。Se（Te）原子链的G-W电子带隙为5.22-5.47（4.44-4.59）eV，其最低限由Godby-Needs（GN）模型得到，上限由Hybertsen-Louie（HL）等离子体极点模型（PPM）得到.基态激子态的结合能范围为2.69和2.72 eV之间的硒链内的HL和GN PPM，分别，和它原来是2.35 eV的碲链与两个近似。对于两种类型的原子链，基态激子波函数沿轴沿着定位在50埃内，并且其能量位于可见光谱内：硒为蓝色[2.50（GN）-2.78（HL）eV]，碲为黄绿色[2.09（GN）-2.28（HL）eV]，这对于可见光谱中的LED应用可能是有用的。
Effects that are not captured by the generalized-gradient density-functional theory have a prominent effect on the structural binding and on the electronic and optical properties of reduced-dimensional and weakly bound materials. Here, we report the exfoliation energy of selenium and tellurium atomic chains with nonempirical van der Waals corrections, and their electronic and optical properties with the G W and Bethe-Salpeter formalisms. The exfoliation energy is found to be within 0.547-0.719 eV/u.c. for the selenium atomic chain, and 0.737-0.926 eV/u.c. for the tellurium atomic chain (where u.c. stands for unit cell), depending on the approximation for the van der Waals interaction and the numerical tool chosen. The G W electronic band gap turned out to be 5.22-5.47 (4.44-4.59) eV for the Se (Te) atomic chains, with the lowest bound obtained with the Godby-Needs (GN), and the upper bound to the Hybertsen-Louie (HL) plasmon-pole models (PPMs). The binding energy of the ground-state excitonic state ranges between 2.69 and 2.72 eV for selenium chains within the HL and GN PPM, respectively, and it turned out to be 2.35 eV for tellurium chains with both approximations. The ground-state excitonic wave function is localized within 50 angstrom along the axis for both types of atomic chains, and its energy lies within the visible spectrum: blue [2.50(GN)-2.78(HL) eV] for selenium and yellow-green [2.09(GN)-2.28(HL) eV] for tellurium, which could be useful for LED applications in the visible spectrum.