Effect of Zn doping on electronic structure and optical properties zincblende GaN (A DFT + U insight)

Abstract

The development of new materials, having exceptional properties in comparison to existing materials is highly required for bringing advancement in electronic and optoelectronic technologies. Keeping this fact, we investigated structural, electronic, and optical properties of zincblende GaN doped with selected Zn concentrations (6.25%, 12.50%, and 18.70%), using the first-principle calculations based on density functional theory with GGA + U. We conducted the entire study using the WIEN2K code. In this study, we calculated various significant parametric quantities such as cohesive energies, formation energies, bulk moduli, and lattice constants along with the study of optical and electronic properties by substituting Ga atoms with Zn atoms in 1 × 2 × 2 supercell. The structural stability is confirmed by studying the phonon dispersion curves which suggest that Zn:GaN material is stable against the 6.25% and 18.70% Zn concentrations while for 12.50%, it shows instability. The Hubbard values U = 0, 2, 4, 6 eV were added to GGA and the electronic properties were improved with the U = 6 eV. Optical absorption was blue shifted while the refractive index and dielectric constant were increased with increasing the Zn concentrations. Electronic properties are enhanced due to the prime contribution of cations (Zn) 3d states. The optical and electronic properties are further discussed in detail in the entire study.

First principles study of the electronic and optical properties of high‐valence transition metal‐doped anatase titanium dioxide

“…The introduction of impurity levels at the bottom of the titanium dioxide conduction band can affect the optical properties, which can be predicted by the frequency dependent complex dielectric function as $${\varepsilon{} \left(\omega \right)={\varepsilon{} }_{1}\left(\omega \right)+i{\varepsilon{} }_{2}\left(\omega \right)}$$ . According to probabilities of direct transitions and Kramers‐Kronig dispersion relation, the real part $${{\varepsilon{} }_{1}\left(\omega \right)}$$ and imaginary part $${{\varepsilon{} }_{2}\left(\omega \right)}$$ can be determined [46]: $$$\vcenter{\openup.5em\halign{$\displaystyle{#}$\cr {\varepsilon{} }_{1}\left(\omega \right)=1+{{2}\over{{\rm \pi }}}{\rho }_{0}\int _{0}^{{\rm \infty }}{{\omega {\rm { {^\prime}}}{\varepsilon{} }_{2}\left(\omega \right)}\over{{\omega {\rm { {^\prime}}}}^{2}-{\omega }^{2}}}d\omega \hfill\cr}}$$$ $$$\vcenter{\openup.5em\halign{$\displaystyle{#}...$$…”

“…According to probabilities of direct transitions and Kramers-Kronig dispersion relation, the real part e 1 w ð Þ and imaginary part e 2 w ð Þ can be determined [46]:…”

Effect of Ti incorporation on the electronic structure and optical properties of MoS2 (a first principle study)

“…The results of optical constants have been presented in the energy range 0-4 eV so that variations in the optical constants may be understood well in the visible range. The optical constants for 3.7%, 5.55%, and 12.5% Ti concentrations were calculated using the Kramers-Kronig equation [46]. The optical constants including optical absorption ( ( ) a w ), refractive index ( ( ) n w ), real dielectric constant ( ( ) r e w ), reflectivity (R(ω)), and extinction coefficient (k) have been calculated and their graphical manifestations have explained in this section.…”

“…The decrease in ( ) r e w is the result of unchanged orientation of dipoles which are unaffected by the external electromagnetic field. Moreover, the extended dielectric humps are due to the disorder effects which are induced in the host MoS 2 lattice by the introduction of impurity [46].…”

Exploring structural, electronic, optical, magnetic, and thermoelectric properties of Pt doped and Pt-Cu/Au co-doped GaN

“…Doping of the GaN with the transition metals [1][2][3] has been studied with great interest as it may bring surprising changes in the electronic and optical properties of host material. The light-matter interaction in terms of the optical constants helps to predict the potential application of the materials for photonic device fabrications.…”