Synthesis and Luminescent Properties of Red Phosphor CaMo_1-<italic>_x</italic>O₄:<italic>x</italic>Eu³⁺ via Hydrothermal Method

A series of red phosphors CaMo1-xO4: xEu3+(x=0.001, 0.005, 0.01, 0.015, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10) were synthesized by hydrothermal method. Techniques such as X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) spectra were used to characterized the samples. The effects of different experimental conditions on the luminescent properties were systematically investigated. The results shows that the synthesized CaMo1-xO4:xEu3+ samples are pristine tetragonal structure. Under 394.6 nm excitation, the emission peaks of samples are at 592 nm, 614 nm, 654 nm and 701 nm, which correspond to 5D0→7F1, 5D0→7F2,5D0→7F3 and 5D0→7F4 transition of Eu3+ ions, respectively. The transition intensity reaches its maximum at 614 nm, and the phosphor emits red light. The optimal doping amount of Eu3+ ions is 0.05, and fluorescence quenching is causedby exchange interaction. The emission intensity decreased with the increasing of temperature. When the temperature increases to 453 K, the luminescence intensity of the sample is 54% of that at 303 K. And the activation energy of CaMo0.95O4:0.05Eu3+ was calculated to be 0.262 eV through fitting the curves of ln(Io/I-1)~1/kT. The samples are located red region on the CIE 1931 chromaticity diagram, indicating that they potential single-doped red luminescent materials for LEDs.