RETRACTED CHAPTER: An Intense Green Emission From ZnO Nanoparticles Coated with MgO

This paper addresses the effects of annealing temperature on photoluminescence of ZnO nanoparticles coated with MgO. ZnO nanoparticles as well as ZnO coated with MgO showed only a sharp UV emission peak positioned at 396 nm at an annealing temperature of 600 °C. As the annealing temperature increased from 600 to 900 °C, the intensity of green emission enhanced monotonously. The green emission intensity at 900 °C is 18 times higher than its value at 700 °C. But at 1,000 °C, green emission intensity decreased. FT-IR spectra of ZnO@MgO showed that MgO evaporation took place with increase of temperature from 700 to 1,000 °C. These results indicates that intensity of green emission depends on thickness of MgO shell coated over the ZnO nanoparticles.