Investigation of photoluminescence properties, thermal stability, energy transfer mechanisms and quantum efficiency of Ca2ZnSi2O7: Dy3+, Eu3+ phosphors

Undoped, Dy3+ doped and Dy3+, Eu3+ co-doped Ca2ZnSi2O7 (CZS) phosphors were successively prepared using the solid state reaction method. The XRD and FE-SEM results revealed that the prepared phosphors have tetragonal crystal structure and agglomeration of particles. The energy band gaps of doped and co-doped phosphors were found to be increased as compared to undoped CZS. From the PL spectra, it was found that the energy transfer from sensitizer (Dy3+) to activator (Eu3+) ion in co-doped CZS: Dy3+, Eu3+ phosphors were mainly due to quadrupole-quadrupole interaction. The prepared CZS: Dy3+, Eu3+ phosphor the emission intensity retained almost 80% at 425 K of that measured at 300 K. The emission color had tuned with the incorporated of Eu3+ ion in CZS: Dy3+ phosphor. The quantum efficiency of CZS: Dy3+, Eu3+ phosphor is 12.88%. All the results of CZS: Dy3+, Eu3+ phosphors showed a great potential application as a white-emitting phosphor for solid state lighting application.