The study of optical and colossal dielectric properties of (Cu, Ga)-doped ZnO nanoparticles

Abstract

In this work, we have studied optical and dielectric properties of (Ga, Cu)-doped ZnO nanoparticles in both theoretical and experimental aspects. In an experimental approach, we have synthesized ZnO, Ga-doped ZnO, Cu-doped ZnO, and (Ga, Cu)-codoped ZnO nanopowder by using combustion method, then calcined nanoparticles were investigated by XRD, SEM, TEM, and UV-vis spectroscopy techniques. In the case of the first-principles calculation, 2×2×2 supercell of ZnO and (Ga, Cu)-co-doped ZnO is modeled. These systems consist of 32 atoms while two-Zn atoms are removed and replaced by Ga and Cu. Thus, it is 12.5% mole (Ga, Cu)-co-doped ZnO, same doping percentage to experiment part. In the study, density functional theory (DFT) study is conducted on VASP using GGA with Hubbard parameter (GGA+U). The supercells are firstly optimized. Then, the study carries on by density of states, and band structures calculation. To summarize, we have successfully fabricated (Ga, Cu)-co-doped ZnO nanoparticles with the particle size of 40 – 50 nm, then, optical, and dielectric properties of Ga and Cu doping on ZnO are studied. From the explored results, it can be concluded that this work successes in enhancement dielectric properties and optical properties of ZnO by Ga and Cu doping. As a result, ZnO could be a higher efficiency dielectric material and photocatalyst under Sun irradiation when it is doped by Ga and Cu ions.