Theoretical insight into magnetic and thermoelectric properties of Au doped ZnO compounds using density functional theory.

Position of impurities at point defects of a compound have an important role in determine the physical or chemical properties of semiconductor materials. Hence, an accurate and efficient theoretical tool is needed in order to have a deep understanding and logic explanation for the physical phenomenon observed. Therefore, first principles calculation was used to investigate the effect of impurities position at point defects of Au atom in the ZnO semiconductor material on thermoelectric and magnetic performance. In this work, density functional theory based on the generalized-gradient-approximation (GGA) and the Boltzmann transport theory have been used to calculate the structural, electronic, magnetic and thermoelectric properties of Au doped ZnO at different point defect's position (interstitial and substitutional). The obtained results give a hexagonal wurtzite structure with the space group of P 63 mc and the formation energy at the interstitial model indicated 0.2331 eV lower rather than the substitution model. This indicated more stable structure at the interstitial sites with n -type degenerated semiconductor characteristic and behaves as a diamagnetic material with highest electronic thermal conductivity. Whereas, the substitution of Zn by Au produces p -type semiconductor characteristics with the presence of magnetism properties (0.916 μ b of total magnetic moment) and enhance the electrical conductivity properties. The Seebeck coefficient obtained is in excellent accord with the experimental data of Au doped ZnO. The result shows that Au doped ZnO can be used in the thermoelectric power generated in magnetic tunnel junction (MTJ) applications. • Magnetic and thermoelectric properties of Au doped ZnO at different point defects are investigated with DFT. • Substitution model show that Au doped ZnO is ferromagnetic, interstitial show paramagnetic behavior. • Hybridization between p-d states are responsible for electrical transport properties and magnetic properties. [ABSTRACT FROM AUTHOR]