Improved Chromaticity and Thermal Stability in White Light Emitting Diode Phosphor BaMgAl10O17: Eu2+, Mn2+

A highly efficient white light emitting diodes phosphor BaMgAl10O17: Eu2+, Mn2+ coating with MgF2 layer was prepared and characterized. The phosphor consisted of a host material BaMgAl10O17 doped with 0.05 mol % Eu2+ and co-doped 0.05 mol % Me. The mechanism of energy transfer between Eu2+ and Mn2+ is dipole-quadrupole. The phosphor coated with MgF2 reveals that the durability is greatly enhanced 9.8 % comparison with uncoated phosphor after thermal degradation tests. The CIE chromaticity coordinates (0.335, 0.330) of the phosphor fabricated light-emitting diodes has a very close to that of the standard white light point of (0.333, 0.333). And the colour rendering index increases from 79 to 85 after the BaMgAl10O17: Eu2+ phosphor co-doped with Mn2+. All the result could conclude that co-doped and surface coated were two promises approaches for improving the colour rendering index of the near UV light-emitting diode and the stability of BaMgAl10O17: Eu2+, Mn2+ phosphor.