On the verification of sol-gel-derived ZnO nanoparticle properties using first-principles calculation

The first-principles calculation was successfully used to verify the electronic and optical properties of ZnO nanoparticles. Prior to calculation, ZnO nanoparticles were experimentally grown through a sol-gel reaction involving zinc acetate dihydrate, methanol and sodium hydroxide. The structural characterization proved the formation of pure hexagonal wurtzite ZnO, and a quantitative Rietveld analysis confirmed the space group of P6 (3) mc with respective atomic coordination of Zn and O. The reliability of Rietveld fitting was confirmed good with a goodness of fit value 2.46. To provide a bridge with experimental result, the ZnO unit cell was built based on the lattice parameters and atomic coordination obtained from Rietveld data. A great agreement between calculated energy band gap (3.08 eV) using LDA + U functional and the absorption band edge spectra (3.06 eV) obtained from experimental approach indicated a valid model. Later, the tabulation of electron density of state confirmed the electronic excitation was dominated by Zn-3d and O-2p states. The corresponding optical properties were calculated with predictive accuracy, and the results were elaborated fundamentally.