Coulomb correlation effects in zinc monochalcogenides

Abstract

Electronic structure and band characteristics for zinc monochalcogenides with zinc-blende- and wurtzite-type structures are studied by first-principles density-functional-theory calculations with different approximations. It is shown that the local-density approximation underestimates the band gap and energy splitting between the states at the top of the valence band, misplaces the energy levels of the Zn-3d states, and overestimates the crystal-field-splitting energy. Regardless of the structure type considered, the spin-orbit-coupling energy is found to be overestimated for ZnO and underestimated for ZnS with wurtzite-type structure, and more or less correct for ZnSe and ZnTe with zinc-blende-type structure. The order of the states at the top of the valence band is found to be anomalous for ZnO in both zinc-blende- and wurtzite-type structure, but is normal for the other zinc monochalcogenides considered. It is shown that the Zn-3d electrons and their interference with the O-2p electrons are responsible for the anomalous order. The typical errors in the calculated band gaps and related parameters for ZnO originate from strong Coulomb correlations, which are found to be highly significant for this compound. The LDA+U approach is by and large found to correct the strong correlation of the Zn-3d electrons, and thus to improve the agreement with the experimentally established location of the Zn-3d levels compared with that derived from pure LDA calculations.

References in corpus (7)

• Linear-response theory and lattice dynamics: a muffin-tin orbital approach
• Implementation of the Projector Augmented Wave LDA+U Method: Application to the Electronic Structure of NiO
• Combining GW calculations with exact-exchange density-functional theory: An analysis of valence-band photoemission for compound semiconductors
• All-electron GW calculation based on the LAPW method: application to wurtzite ZnO
• Calculated spin-orbit splitting of all diamond-like and zinc-blende semiconductors: Effects of p1/2 local orbitals and chemical trends
• All-electron Exact Exchange Treatment of Semiconductors: Effect of Core-valence Interaction on Band-gap and $d$-band Position
• Electronic structure and band parameters for ZnX (X = O, S, Se, Te)

Cited by in corpus (6)

• Electronic structure and optical properties of ZnX (X=O, S, Se, Te)
• Comparative Study of Structural and Electronic Properties of Cu-based Multinary Semiconductors
• Combined hybrid functional and DFT+$U$ calculations for metal chalcogenides
• Magnetism in Cr-doped ZnS: Density-functional theory studies
• Linear-response calculation of the effective Coulomb interaction between closed-shell localized electrons: Cu, Zn, and ZnO
• Ab-initio semi-classical electronic transport in ZnSe: The role of inelastic scattering mechanisms