Physical properties and mechanical stability of AlCu:XO2 (X=Hf, Zr) alloys from density functional theory (DFT): Prediction and analysis for photocatalysis and electronic devices applications

Abstract

The electronic, optical and mechanical properties of AlCu:XO2 alloys (X=Hf, Zr) are investigated for the first time through the Density Functional Theory (DFT). The aim of this work is to evaluate the impact of aluminum-copper alloys on the physical response of high-k materials for both electronic and photocatalysis devices applications. It will be shown that 25% of Al is the appropriate composition leading to improved electrical and optical properties. Whereas by increasing the AlCu content (25%), the band gap energy decreases to reach 2.96 and 2.37 eV for HfO2 and ZrO2 respectively. A shift of the optical absorption to the visible light region is also observed making these configurations adequate for photocatalytic devices applications. The presence of AlCu alloy in these oxides shows that it is possible to reduce or suppress the defect states according to the electronic structure and enhance the mechanical stability of the AlCu:XO2 alloys.