Using first-principles calculations, we have studied the band-gap modulation as function of applied strain in black phosphorene (BP). Dynamical stability has been assessed as well. Three cases have been considered, in the first and second, the strain was applied uniaxially, in the x- and y-axis, separately. In the third, an isotropic in-plane strain was analyzed. Different strain percentages have been considered, ranging from 4% to 20%. The evolution of the band-gap is studied by using standard DFT and the G0W0 approach. The band-gap increases for small strains but then decreases for higher strains. A change in electronic behavior also takes place: the strained systems change from direct to indirect band-gap semiconductor, which is explained in terms of the s and p-orbitals overlap. Our study shows that BP is a system with a broad range of applications: in band-gap engineering, or as part of van der Waals heterostructures with materials of larger lattice parameters. Its stability, and direct band-gap behavior are not affected for less than 16% of uniaxial and biaxial strain. Our findings show that phosphorene could be deposited in a large number of substrates without losing its semiconductor behavior.

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Using first-principles calculations, we have investigated the structural, electronic, and optical properties of phosphorene and arsenene, group V two-dimensional materials. They have attracted the scientific community’s interest due to their possible applications in electronics and optoelectronics. Since phosphorene and arsenene are not planar monolayers, two types of structures were considered for each system: puckered and buckled arrangements. Computations of band gap were performed within the GW approach to overcome the underestimation given by standard DFT and predict trustable band gap values in good agreement with experimental measurements. Our calculated electronic band gaps lie in the range from near-infrared to visible light, suggesting potential applications in optoelectronics devices. The computed electronic band gaps are 2.95 eV and 1.83 eV for blue and black phosphorene systems. On the other hand, the values for buckled and puckered arsenene are 2.56 eV and 1.51 eV, respectively. Moreover, the study of the optical properties has been dealt by computing the dielectric function imaginary part, which was obtained using the Bethe–Salpeter approach. The use of this technique allows the consideration of excitonic effects. Results indicate strong exciton binding energies of 830 meV for blue phosphorene, 540 meV for black phosphorene, 690 meV for buckled arsenene, and 484 meV for puckered arsenene. The results of our study suggest the possibility of using these materials in electronic and optoelectronic devices.

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