Abstract:
BACKGROUND: The structurals stability, electronic structure, density of states (DOS), and optical properties of B-doped arsenene under biaxial tensile and compressive strains were investigated using density functional theory (DFT) calculations. The doping system was found to exhibit good stability. The introduction of B atom transformed the originally indirect band gap of arsenene into a direct band gap. Under compressive strain, the band gap remained direct, gradually decreasing in value. In contrast, under tensile strain, the direct band gap occurred a transition into an indirect band gap, of which value initially increasing and then decreasing with an increasing strain. The static dielectric constant was increased under both compressive and tensile strains, but compressive strain had a stronger effect. Compressive strain led to an increase in the imaginary peak of the dielectric function, while tensile strain resulted in a decrease. Moreover, as compressive strain increased, the absorption and loss function peak initially blue-shifted and then red-shifted, while tensile strain caused a gradual red-shift of the absorption peak.
METHODS: All DFT calculations were performed using Quantum Espresso software; the structures were optimized using generalized gradient approximation (GGA-PBE), and electronic structure and optical properties are performed using Heyd-Sceria-Ernzerhof (HSE06). The cut-off energy was set as 70 Ry, the Monkhorst-Pack grid was set to 10 × 10 × 1, the atomic convergence criterion was set as 1.0 × 10-6 Ry, and the convergence criterion of interatomic force was set as 1.0 × 10-4 Ry/Bohr.
摘要:
背景:结构稳定性,电子结构,态密度(DOS),使用密度泛函理论(DFT)计算研究了B掺杂砷烯在双轴拉伸和压缩应变下的光学性质。发现掺杂体系表现出良好的稳定性。B原子的引入将砷烯最初的间接带隙转变为直接带隙。在压缩应变下,带隙仍然是直接的,价值逐渐下降。相比之下,在拉伸应变下,直接带隙发生了向间接带隙的过渡,其价值最初随着应变的增加而增加,然后随着应变的增加而减少。静态介电常数在压缩和拉伸应变下都增加,但是压缩应变有更强的影响。压缩应变导致介电函数的虚峰增加,而拉伸应变导致减少。此外,随着压缩应变的增加,吸收和损失函数峰最初蓝移,然后红移,而拉伸应变导致吸收峰逐渐红移。
方法:所有DFT计算均使用QuantumEspresso软件进行;使用广义梯度近似(GGA-PBE)优化结构,使用Heyd-Sceria-Ernzerhof(HSE06)进行电子结构和光学性质。截止能量设置为70Ry,Monkhorst-Pack网格设置为10×10×1,原子收敛准则设置为1.0×10-6Ry,原子间力的收敛准则为1.0×10-4Ry/Bohr。