Functions of tensile and compressive strain on electronic and optical properties of B-doped monolayer arsenene.

Context: 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.

Method: 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 Ry, and the convergence criterion of interatomic force was set as 1.0 × 10 Ry/Bohr.