Multicolor-tunable Ca8MgBi(PO4)7: Ce3+, Tb3+, Mn2+phosphors under dual-channel excitation

A series of color-tunable phosphors Ca8MgBi(PO4)(7)(CMBPO): Ce3+, Tb3+, Mn(2+)have been prepared by high-temperature solid-state reaction process. The X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), photoluminescence excitation (PLE) and emission (PL) spectra were utilized to characterize the samples. Through the dual-channel excitation process, energy transfers (ET) occur simultaneously between Ce3+ -> Tb(3+)and Ce3+ -> Mn2+. In addition, ETs process from Ce(3+)to Tb3+/Mn(2+)has been proved to be a resonance type, which is manifested by dipole-dipole/dipole-quadrupole interactions. Moreover, the emission band of CMBPO:0.20Mn(2+)distributed in the red and far-red regions matches well with the red light wavelength required for phytochrome protein (P(R)and P-FR), indicating that the phosphor can be used as a new type of red luminescent powder absorbed by plant photosensitive pigment and promoted plant growth. Importantly, the CMBPO:0.10Ce(3+), 0.08Tb(3+),zMn(2+)can emit white light by properly tuning the ratio of Tb(3+)and Mn(2+)under ultraviolet (UV) excitation. The results suggested that the present phosphors can be a potential candidate for white light emitting diodes (WLEDs).