Pseudopotential Band Structure of ZnO

Abstract

The empirical pseudopotential method is used to compute the band structure, density of states, and reflectivity of hexagonal zinc oxide. The local approximation is assumed, on the basis of recent photoemission experiments which showed that the zinc core 3d band lies deep below the valence band. The calculation succeeds in identifying the reflectivity peaks, but gives stronger amplitudes than are observed, and these identifications are shown to fit well into the systematics of the other three zinc chalcogenides. Reasonable agreement is also obtained with the experimental locations of the maxima in the density of states and with the large value of the valence bandwidth.La methode des pseudopotentiels empiriques a Bt6 utilisee pour calculer la structure des bandes, la densit6 des 6tats et la reflectivit6 de l'oxide de zinc hexagonal. On suppose une approximation locale, car les resultats recents en photo-6mission ont montre que la bande 3d du zinc est beaucoup plus profonde que la bande de valence. Le calcul reussit B identifier la structure de reflectivite, mais donne des amplitudes plus grandes que celles qui sont observbes, e t ces identifications sont en bon accord avec le systeme des autres trois chalcogenides de zinc. Un accord raisonable est aussi obtenu avec la position des maxima de densite d'btats determinee experimentalement e t avec la grosse largeur de la bande de valence.

Direct measurement of density-of-states effective mass and scattering parameter in transparent conducting oxides using second-order transport phenomena

“…This being the case, we may conclude that ZnO has a single-valley minimum in the conduction energy band and that the constant energy surface must be spherical to within experimental uncertainty. The singlevalley minimum of ZnO is predicted by theory, 19 but the uncertainty in the plasma frequency data makes it difficult to be certain of the spherical nature of the energy surface. We note that ZnO is hexagonal and that our films have a (200) orientation.…”

“…We constructed equipment to measure these four transport coefficients simultaneously over a temperature range of 30-350 K for thin, semiconducting films deposited on insulating substrates. We measured these coefficients for rf magnetron-sputtered zinc oxide, both doped and undoped, with aluminum with carrier concentrations in the range of 1x10 19 -5x10 20 cm The measured scattering parameter changed from close to zero to 1.5 as the carrier concentrations increased. The scattering parameter, Seebeck, and mobility vs. temperature data support neutral impurity scattering in the undoped material and ionized impurity scattering in the Al-doped ZnO.…”

Studies of electronic structure of ZnO grain boundary and its proximity by using spatially resolved electron energy loss spectroscopy

“…Several minor peaks observed at 3.86, 5.82, 9.5, 13, and 21.7 eV are determined to be the interband transitions. 12,13 Among them, the peaks at 5.82 and 9.5 eV are assigned to the transitions from the O 2p states to the unoccupied conduction band while the peaks at 13 and 21.7 eV are ascribed to the transitions arise from Zn 3d and O 2s levels, respectively. 13 The loss at 3.86 eV is assumed to be of defect origin that associates with the excitations from the deep states in the gap.…”

“…12,13 Among them, the peaks at 5.82 and 9.5 eV are assigned to the transitions from the O 2p states to the unoccupied conduction band while the peaks at 13 and 21.7 eV are ascribed to the transitions arise from Zn 3d and O 2s levels, respectively. 13 The loss at 3.86 eV is assumed to be of defect origin that associates with the excitations from the deep states in the gap. 12 The loss function is consistent with that of Hengehold et al taken by using a single crystal.…”

Investigation of the Reflectivity Spectrum of the a-Plane Oriented ZnO Epilayers Grown by Plasma-Assisted Molecular Beam Epitaxy from the Gaussian Distribution

“…[11] gave a precious data to the researchers investigating exclusively the optical constants of ZnO. All these works show the important roles which play the zinc oxide in the new technology reason why the authors continued to study it for more information and applications [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30]. Beside the experimental methods, certain authors used models to investigate the physical properties of the zinc oxide or others semiconductors.…”