Investigation on the Synthesis and Photoluminescence of CaMoO4:Eu3+ Microspheres

Eu3+ doped CaMoO4 microspheres were synthesized via a facile hydrothermal method assisted by the citric acid additive. The structure and morphology of the samples were examined by X-ray diffractometer (XRD) and scanning electron microscopy (SEM), and the properties of the photoluminescence emission from the samples were investigated with spectroscopic technique. The XRD results revealed that the hydrothermally formed CaMoO4:Eu3+ phosphor has single-phase scheelite-type tetragonal structure. The SEM observation demonstrated that the samples have sphere-like morphologies and their diameters were about 3-4 µm. Meanwhile, the influence of the citric acid on the formation of CaMoO4:Eu3+ was also investigated. The formation mechanism of CaMoO4:Eu3+ microspheres was explored based on the time-dependent experimental observation. The study on the luminescence spectra showed that CaMoO4:Eu3+ microspheres can be effectively excited at 395 nm, and good luminescence emission can be obtained at around 614 nm, which is attributed to the transition of 5D0 --> 7F2 from Eu3+. The current study suggests that CaMoO4:Eu3+ red phosphor is a potential candidate for white light-emitting diodes (WLEDs) application.