Controlled preparation and properties of flaky alumina for white LEDs

Light emitting diode(LED)has been widely applied in the field of lighting and displaying.Flaky alumina powders was synthesized using aluminum nitrate and urea as the raw materials,PEG 2000 as the surfactant and aluminum fluoride as the additive.The YAG∶Ce3+ phosphor was synthesized with flaky alumina by the method of hydrothermal-pyrolysis.The structure and morphologies of the synthesized samples were investigated by XRD,SEM and FM techniques.The results showed that after 24 hours' thermal reaction at 120℃,by adding appropriate amount of aluminum fluoride,regular hexagon tabular alumina with particle size of 3-4μm and thickness of 0.2-0.3μm can be obtained through high-temperature calcination.The additive aluminum fluoride plays an important role in controlling the particle size of the alumina.This study explores the application of the flaky alumina powders,which was synthesized by the method of hydrothermal-pyrolysis and served as the base LED phosphor powder,in the phosphor powder YAG∶Ce3+ and obtains optimized results.