Calculated electronic, transport, and related properties of zinc blende boron arsenide (zb-BAs)

Abstract

We present the results from ab-initio, self-consistent density functional theory (DFT) calculations of electronic, transport, and bulk properties of zinc blende boron arsenide. We utilized the local density approximation potential of Ceperley and Alder, as parameterized by Vosko and his group, the linear combination of Gaussian orbitals formalism, and the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF), in carrying out our completely self-consistent calculations. With this method, the results of our calculations have the full, physical content of density functional theory (DFT). Our results include electronic energy bands, densities of states, effective masses, and the bulk modulus. Our calculated, indirect band gap of 1.48 eV, from Γ to a conduction band minimum close to X, for the room temperature lattice constant of 4.777 Å, is in an excellent agreement with the experimental value of 1.46 ± 0.02 eV. We thoroughly explain the reasons for the excellent agreement between our findings and corresponding, experimental ones. This work provides a confirmation of the capability of DFT to describe accurately properties of materials, if the computations adhere strictly to the conditions of validity of DFT, as done by the BZW-EF method.

Band structure and carrier effective masses of boron arsenide: Effects of quasiparticle and spin-orbit coupling corrections

“…Additional spinorbit effects around the Γ point include an avoided crossing in the conduction band, as well as changes to the valence band curvatures. We subsequently evaluated the electron and hole effective-mass values using the GW+SO band structure data; a comprehensive list of effective masses is presented in Table 3 and is in agreement with work done by Nwigboji et al 11 We find that along all directions the valence band splits into the heavy hole (hh), light hole (lh), and spin-orbit hole (soh). The spin-orbit splitting along the Γ-K direction results in six nondegenerate bands due to the lack of inversion symmetry in BAs.…”

Electronic band structure and optical properties of boron arsenide

“…Our results are in reasonable agreement with other calculations using similar approaches (DFT and hybrid DFT, see Table I). 12,16,24,29,31 For the QSGW calculations, however, we took advantage of the Questaal code, which allows one to fit a quadratic function to a set of points forming an icosohedron about the band edges and derive the effective mass tensor. We therefore expect this approach to provide more accurate results than simply fitting to the bands along high symmetry directions (although for electrons the two approaches should be equivalent).…”

“…30 Further studies using techniques beyond standard DFT, including GW , report values from 1.48−2.049 eV. 23,24,26,27,31 In this Rapid Communication, we employ the relativistic quasiparticle self-consistent GW (QSGW ) approach 32 to compute the band structure and optical properties of BAs. The GW approximation can be used to correct the one-electron eigenvalues obtained from DFT within a many-body quasiparticle framework, including the exchange and correlation effects in a self-energy term dependent on the one-particle Green's function G and the dynamically screened Coulomb interaction W .…”

Reduced k-points based computationally efficient band structure approach for UTB device simulation

“…The main reason for high computational time of the TB model, with large number of atomic layers, is the increasing dimension of the TB hamiltonian that needs to be diagonalized for the entire k-space in the irreducible Brillouin zone (BZ). Furthermore, this problem will become more serious for some materials of recent interest that have lower lattice constants, such as Diamond (3.567Å [16]), cubic-BN (3.615Å [16]), BAs (4.777Å [17]), SiC (4.359Å [18]), AlN (4.394Å [19]), and GaN (4.512Å [19]), for which even small channel thicknesses will have a large number of atomic layers. Therefore, given the well documented advantage of the sp 3 d 5 s * TB model, we try to extend its usability for larger number of atomic layers, while being computationally efficient compared to the full band structure approach, without sacrificing its accuracy and versatility.…”