Abstract: Using NH₄HCO₃-NH₃·H₂O as a mixed precipitator, CaMoO₄：Eu³⁺ red phosphor was successfully synthesized by chemical co-precipitation method. The processes of thermal decomposition and phase formation for CaMoO₄：Eu³⁺ precursor were analyzed by TG-DTA and XRD. Compared with solid-state method, both surface morphology and luminescence properties of CaMoO₄：Eu³⁺ red phosphor using precipitators NH₄HCO₃, NH₃·H₂O and NH₄HCO₃-NH₃·H₂O are evaluated by means of SEM and PL respectively. After calcination at 700℃, the precursor is completely converted to a single scheelite structure of CaMoO₄：Eu³⁺. Photoluminescence intensity of the phosphor reaches the maximum value at 900℃. The phosphor prepared by using mixed precipitator is uniform spherical particle, and has no aggregation with average size of 0.9μm. Compared with solid-state method, the Eu-O CTS of the red phosphor slightly shifts toward long wavelength. The strong electron absorbability of ⁷F₀→⁵L₆ (394nm) and ⁷F₀→⁵D₂ (465nm) effectively improves the performance of red phosphor. In addition, the photoluminescent intensity from the mixed precipitation is increased to 2 times of that of the red phosphors prepared by solid-state method.

Key words: co-precipitation, CaMoO₄：Eu³⁺, red phosphor