Electronic and optical properties of the buckled and puckered phases of phosphorene and arsenene

Abstract

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.

Tuning Gaps and Schottky Contacts of Graphene/Phosphorene Heterostructures by Vertical Electric Field and Strain

“…All the geometrical structures are fully relaxed until the forces are converged to 10 meV/Å. Calculated lattice parameters for the pristine graphene and rectangular phosphorene are a = 2.457 Å, a = 3.307 Å and b = 4.587 Å, which are in good agreement with theoretical [ 24 , 38 , 50 , 51 ] and experimental values ( a = 2.46 Å, a = 3.35 Å and b = 4.62 Å) [ 3 , 9 ].…”

“…Despite the use of a large 2D supercell, Figure 3 b shows that puckered phosphorene is a direct semiconductor with a CBM and a VBM at and has a DFT band gap of about 0.9 eV, in agreement with previous calculations based on the same methodology [ 4 , 13 , 58 , 59 ]. We know that the inclusion of many-body excitation aspects, e.g., within the GW approximation [ 60 ], increases both the Fermi velocity of graphene to a value which is slightly above m/s [ 14 ] and the quasi-particle gap of phosphorene toward 1.6, or even 1.83 eV [ 24 , 61 ]. The computation of quasi-particle corrections is only possible for systems with a few atoms in the unit cell.…”

“…Band-gap engineering with in-plane or out-of-plane strain may result in direct–indirect semiconductor and metal–insulator transitions [ 5 , 15 , 16 ]. An extraordinary phenomenon is the observation of excitons with large binding energies, which generally appear in 2D semiconductors because of reduced screening [ 17 ]; moreover, strongly layer-dependent exciton binding energies up to slightly below 1 eV have been observed for phosphorene monolayers [ 18 , 19 , 20 , 21 , 22 , 23 , 24 ]. Other remarkable anisotropic properties concern the thermal transport [ 25 ] and the polarization-dependent optical spectra [ 24 , 26 ].…”

Adjustment of optical absorption in phosphorene through electron–phonon coupling and an electric field

“…Much like graphene and other planar 2D materials, the out-of-plane (p z or p) orbitals play a predominant role in electronic transport within such lattices. However, identical atoms on both sublayers lead to a two-band tight-binding model for effective responses of the momentumdependent Hamiltonian for a one-orbital p z -like configuration (confirmed through projected density of states), 37,43 given by…”

Band gap engineering in pyridyl-functionalized two-dimensional (2D) CuSCN coordination polymers

“…resembles that of the 2D puckered structure of black phosphorene or puckered arsenene. 33,34 The bond length between Cu and 3-XPy changed slightly with the electron-donating strength of the co-ligands. 3-OMePy, with the highest electron-donating ability, showed the shortest Cu-L bond length at 2.04 Å while that of Py was 2.05 Å.…”