Photoluminescence and energy transfer mechanism of a novel tunable color phosphor Na2MgSiO4:Tb3+, Eu3+

A series of novel tunable green-yellow-red emitting Na2MgSiO4(NMSO): Tb3+, Eu3+ phosphors have been synthesized by a traditional solid state reaction. The PL and PLE properties of NMSO: Tb3+, Eu3+ have been investigated. Under excitation at 376 nm, the phosphors exhibit the characteristic of Tb3+ and Eu3+ emissions with the strongest peaks located at 546 nm (green) and 615 nm (red), respectively. Moreover, the emission intensities of both Tb3+ and Eu3+ remarkably vary with Eu3+ concentration, and the optimized doping concentration of Tb3+ ions and Eu3+ ions were confirmed to 4.00% mol and 0.10% mol, respectively. The dominating energy transfer from Tb3+ to Eu3+ in the NMSO host were investigated and the mechanism was demonstrated to be the resonant type via a non-radiative dipole-dipole interaction. The critical distances between donor-activator was calculated to be 16.76 Å. The hues of the studied phosphors can be tuned in the novel single-phase NMSO host by varying the ratio of Eu3+ to Tb3+ ions. All the results indicating that the phosphor may potentially be used as a tunable green-yellow-red emitting phosphor for UV light-emitting diodes.