Effects of Ti content on the optical and structural properties of the Ti-doped ZnO nanoparticles

This study investigates the effect of Ti content on the optical and structural properties of the Ti-doped ZnO (TixZn1−xO) nanoparticles by x-ray diffraction, scanning electron microscopy, photoluminescence and Raman scattering measurements. A dependence of luminescent properties and crystal structure upon Ti content has been found. The band-edge-luminescence (BEL) intensity of Ti0.10Zn0.90O at room temperature was nearly 1.7 times higher than that of ZnO. The enhanced BEL intensity is attributed to a decrease in the oxygen-vacancy density. However, the lower BEL intensity of Ti0.15Zn0.85O than Ti0.10Zn0.90O is attributed to an increase in the probability of nonradiative recombination. In addition, the intensity of the x-ray diffraction peaks remarkably decreases with increasing Ti content, suggesting weakened crystallinity.