Morphological and optical property of spherical ZnO nanoparticles

We report here a simple wet chemical method of synthesizing spherical ZnO particles without using any surfactants. FESEM images revealed the formation of spherical ZnO nanoparticles of diameter ∼250 nm. The composition of the material was confirmed using energy dispersive X-ray spectroscopy in situ with FESEM. UV–Visible absorption spectroscopy revealed the strong absorption at ∼378 nm. The nanoparticles have band gap ∼3.61 eV as calculated from the absorption data. The enhancement of band gap occurs due to quantum confinement effect. Raman spectrum revealed the formation of ZnO with the presence of the 2E2, E2 and A1t vibration mode. The spherical ZnO nanoparticles exhibit strong PL emission at 420 nm owing to deep level defect states.