Nonradiative energy transfer from Mn2+ to Eu3+ in K2CaP2O7:Mn2+,Eu3+ phosphor

A series of color tunable phosphors K2Ca1−x−yP2O7:xMn2+, yEu3+ are synthesized by solid state reaction method. The energy transfer phenomenon from Mn2+ to Eu3+ has been observed in the Mn2+/Eu3+ codoped non-magnetic K2CaP2O7 host, which was confirmed by PL spectra and decay curves. The Mn2+→Eu3+ energy transfer is controlled by quadrupole–quadrupole interaction between sensitizer and activator. The maximum efficiency of energy transfer is estimated to be 33% with x=0.125 and y=0.03 in K2Ca1−x−yP2O7:xMn2+, yEu3+ phosphor. The phosphors can emit light from green to yellow and eventually to orange under 400 nm excitation by changing the Mn2+/Eu3+ content ratio, indicating that K2CaP2O7: Mn2+, Eu3+ would be potential candidates for use in lighting and displays applications.