Luminescence properties and energy transfer of host sensitized CaMoO4:Tb3+ green phosphors

A series of CaMoO4:xTb3+ (x=0.01, 0.03, 0.05, 0.07, 0.09, 0.15 and 0.20) phosphors in pure phase were prepared via high temperature solid-state reaction approach. The crystal structure of the phosphors was investigated by X-ray diffraction (XRD), and the optical properties were investigated by Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-Vis) and photoluminescence (PL) spectroscopy. The PL spectra illustrated that these phosphors could be efficiently excited by the charge transfer band of the host and the energy transfer efficiency from the host to the doped activator reached 60% when the doping concentration of the activator Tb3+ was 20 mol.%. The concentration quenching occurred at x=10 mol.%, from which the critical distance of activator was calculated to be about 1.14 nm. The CIE coordinates were estimated to be close to the standard green value. The host sensitized samples had potential application as green phosphors.