First principles study on electronic structure and optical properties of quaternary arsenide oxides YZnAsO and LaZnAsO

Abstract

The electronic structure and optical properties of the tetragonal phase quaternary arsenide oxides YZnAsO and LaZnAsO were studied using density-functional theory (DFT) within generalized gradient approximation (GGA). The band structure along the higher symmetry axes in the Brillouin zone, the density of states (DOS) and the partial density of states (PDOS) were presented. The calculated energy band structures show that both YZnAsO and LaZnAsO are indirect gap semiconductors with band gap of 1.173 1 eV and 1.166 5 eV, respectively. The DOS and PDOS show the hybridization of Y-O/La-O atom orbits and Zn-As atom orbits. The dielectric function, reflectivity, absorption coefficient, refractive index, electron energy-loss function and optical conductivity were presented in an energy range from 0 to 25 eV for discussing the optical properties of YZnAsO and LaZnAsO.

Investigation of structural and electronic properties by pnictogen substitution in the layered oxypnictides (LaO)ZnPn (Pn = P, As, Sb)

“…In (LaO)Cu Ch systems, Cu 3d states spread along VB and are hybridized with Ch p states. On the other hand, in (LaO)Zn Pn systems, Zn 3d is strongly localized at the bottom of VB from the PE spectra and the first‐principles study . Furthermore, (LaO)Zn Pn systems show Pn p and Zn 4s characteristics in both VB and conduction band (CB), unlike that of (LaO)Cu Ch systems.…”

“…On the other hand, in (LaO)ZnPn systems, Zn 3d is strongly localized at the bottom of VB from the PE spectra [11] and the first-principles study. [22,23] Furthermore, (LaO)ZnPn systems show Pn p and Zn 4s characteristics in both VB and conduction band (CB), [18] unlike that of (LaO)CuCh systems. However, the effect of Pn substitution in the (LaO)ZnPn system on the band alignment and the contributions of sub-Pn p (p x , p y , p z ), as well as Zn 4s orbitals in the VB and CB, are not clear yet.…”