Abstract
ZnO nanoparticles were synthesized using the sol–gel method with a variation on the sol aging time and refined structural data were taken to simulate the synthesized sample in a first-principles calculation. The ZnO nanoparticles aged at 36 h and showed profound properties with high crystallinity and good visual fit in a Rietveld analysis. Optical analysis revealed only small variation in energy band gap for all samples, ranging between 3.08–3.12 eV, with the presence of oxygen vacancy defects. In first-principles calculation, several exchange-correlation functionals, including LDA, GGA-PBE, GGA-PBESol, LDA + U, GGA-PBE + U and GGA-PBESol + U, were tested to converge with the lowest optimized lattice deviation. GGA-PBE + U (Ud,Zn = 10 eV and Up,O = 6.1 eV) showed the lowest lattice deviation and reproduced the experimental band gap. The ZnO supercell structure with an oxygen vacancy showed that a defect state appears in the valence band and acts as a deep donor.
Published Version
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