Ab‐initio investigation of structural, electronic and optical properties for three phases of ZnO compound

Abstract

The complex density-functional theory (DFT) calculations of structural, electronic and optical properties for the three phases: wurtzite (B4), zincblende (B3) and rocksalt (B1) of ZnO compound have been reported using the full-potential linearized-augmented plane-wave (FP-LAPW) method as implemented in the WIEN2k code. We employed both the local-density approximation (LDA) and the generalizedgradient approximation (GGA), which is based on exchange -correlation energy optimization to calculate the total energy. Also, we have used the Engel -Vosko GGA formalism, which optimizes the corresponding potential for band-structure calculations. The 3d orbitals of the Zn atom were treated as the valence band. The calculated structural properties (equilibrium lattice constant, bulk modulus, etc.) of the wurtzite and rocksalt phases are in good agreement with experiment. The B4 structure of ZnO is found to transform to the B1 structure with a large volume collapse of about 17%. The phase transition pressure obtained by using LDA is about 9.93 in good agreement with the experimental data. B1-ZnO is shown to be an indirect bandgap semiconductor with a bandgap of 1.47 eV, which is significantly smaller than the experimental value (2.45 ± 0.15 eV). While B3 and B1 phases have direct bandgap semiconductors with bandgaps 1.46 and 1.57 eV, respectively. Also, we have presented the results of the effective masses. We present calculations of the frequency-dependent complex dielectric function ( ) ε ω and it zero-frequency limit 1 (0) ε . The optical properties of B4 phase show considerable anisotropic between the two components. The reflectivity spectra has been calculated and compared with the available experimental data.

Ab initio study of structural, dielectric, and dynamical properties of zinc-blende ZnX (X=O, S, Se, Te)

“…Khenata et al [14] used the full-potential linearized-augmented plane-wave plus local orbital (FLAPW + LO) method to calculate the elastic, electronic and optical properties of ZnS, ZnSe and ZnTe under pressure. Charifi et al [15] used the FLAPW method to investigate the structural, electronic and optical properties for three phases of ZnO compound. Even though there exists a number of calculations for the electronic structure, optical and dynamical properties using different methods, few linear-response calculation exist for these compounds.…”

“…From a theoretical point of view, there have been many empirical and ab initio calculations of the structural, electronic, optical and dynamical properties for ZnX compound [6][7][8][9][10][11][12][13][14][15]. Agrawal et al [6] used the ab initio method for calculating the electronic, structural, and dynamical properties of Zn-based semiconductors.…”

Optoelectronic and transport properties of Zintl phase KBa2Cd2Sb3 compound

“…Usually EVGGA was obtained by optimizing the exchange-correlation potential V xc instead of the corresponding energy E xc . This approach yields better band splitting and structural properties that mainly depend on the accuracy of the exchange-correlation potential [36][37][38] therefore this functional is selected for further explanation of partial density of states (PDOS). The calculated total and partial density of states are shown in Fig.…”

Effect of NaOH solution on surface textured ZnO: Al films prepared by pulsed direct current magnetron sputtering

“…ZnO, a wide band gap semiconductor, is a promising optoelectronic material [1][2][3][4][5][6][7][8]. In particular, ZnO:Al (AZO) thin film has attracted much attention as the front electrode in silicon-based thin film solar cells in recent years due to its low cost, low resistivity, high transparency in the visible wavelength range, non-toxicity and stability under hydrogen plasma environment [9][10][11].…”