Luminescence properties and efficient energy transfer investigations of inverse garnet-type Mg 3 Y 2− x − y Ge 3 O 12 : x Tb 3+ , y Eu 3+ multicolor phosphor

Tb 3+ and/or Eu 3+ doped Mg 3 Y 2 Ge 3 O 12 phosphors were synthesized successfully through solid-state reaction. The X-ray diffraction (XRD) patterns, photoluminescence (PL), fluorescence decay curve and energy transfer behavior of the samples were studied in detail. XRD patterns show all samples are attributed to inverse garnet structure. Under UV excitation, the singly doped phosphors with Tb 3+ and Eu 3+ ions showed green and red characteristic emission. The emission color of Mg 3 Y 2 Ge 3 O 12 :Tb 3+ , Eu 3+ can be adjusted by the corresponding Tb 3+ –Eu 3+ energy transfer, which also demonstrated excellent thermal stability at 448 K (78.09%). These results indicate that the Mg 3 Y 2 Ge 3 O 12 :Tb 3+ , Eu 3+ phosphors will have potential use in n-UV pumped LED devices.