Luminescence and energy transfer of warm white-emitting phosphor Mg 2 Y 2 Al 2 Si 2 O 12 :Dy 3+ ,Eu 3+ for white LEDs.

A series of Mg 2 Y 2 Al 2 Si 2 O 12 :Dy 3+ ,Eu 3+ phosphors were synthesized by the solid-state method. The luminescent properties and crystal structures of the Mg 2 Y 2 Al 2 Si 2 O 12 :Dy 3+ ,Eu 3+ phosphors were analyzed. The XRD results show that the synthesized Mg 2 Y 2 Al 2 Si 2 O 12 :Dy 3+ ,Eu 3+ phosphors are of pure phase. Mg 2 Y 2 Al 2 Si 2 O 12 :Dy 3+ can emit blue and yellow light under 367 nm light excitation; when doped with Eu 3+ , there is an obvious energy transfer from Dy 3+ to Eu 3+ , and warm white light can be realized by adjusting the concentrations of Dy 3+ and Eu 3+ in Mg 2 Y 2 Al 2 Si 2 O 12 . A warm white LED device was fabricated by combining Mg 2 Y 1.88 Al 2 Si 2 O 12 :0.05Dy 3+ ,0.07Eu 3+ and a UV LED chip (370 nm) under a voltage of 3.2 V and current of 5 mA, the characteristics of the white LED being CIE = (0.4071, 0.3944), CCT = 3500 K and CRI = 91.3.