Warm-white-light emitting diode utilizing a single-phase full-color Ba3MgSi2O8:Eu2+, Mn2+ phosphor

The ${\mathrm{Ba}}_3{\mathrm{MgSi}}_2{\mathrm{O}}_8:{\mathrm{Eu}}^{\text{2+}},$ ${\mathrm{Mn}}^{\text{2+}}$ shows three emission colors: 442, 505, and 620 nm. The 442 and 505 nm emission originate from ${\mathrm{Eu}}^{\text{2+}}$ ions, while the 620 nm emission originates from ${\mathrm{Mn}}^{\text{2+}}$ ions. The excitation bands of three emission colors are positioned around 375 nm. Electron paramagnetic resonance measurement demonstrates that ${\mathrm{Eu}}^{\text{2+}}$ ions are occupied with three different ${\mathrm{Ba}}^{\text{2+}}$ sites. The red emission of ${\mathrm{Mn}}^{\text{2+}}$ ions has a long decay time of 750 ms due to persistent energy transfer from oxygen vacancies to ${\mathrm{Mn}}^{\text{2+}}$ ions, while the blue and green bands of ${\mathrm{Eu}}^{\text{2+}}$ ions have decay times of 0.32 and 0.64 μs, respectively. The fabricated white-light emitting diode using a 400-nm-emissive chip with a white-light emitting ${\mathrm{Ba}}_3{\mathrm{MgSi}}_2{\mathrm{O}}_8:{\mathrm{Eu}}^{\text{2+}},$ ${\mathrm{Mn}}^{\text{2+}}$ phosphor shows warm white light and higher color stability against input power in comparison with a commercial GaN-pumped $({\mathrm{Y}}_{\text{1−x}}{\mathrm{Gd}}_x{)}_3({\mathrm{Al}}_{\text{1−y}}{\mathrm{Ga}}_y{)}_5{\mathrm{O}}_{12}:{\mathrm{Ce}}^{\text{3+}}$ phosphor.