Highly thermostable and color tunable Dy3+/Sm3+ co-doped germanate phosphors for solid-state lighting

Currently, developing thermostable and color tunable phosphor via energy transfer strategy is a significant research topic in solid-state lighting field. Herein, the sensitizer Dy3+ and activator Sm3+ are solidly dissolved into the Ba2Y2Ge4O13 (BYGO) matrix to prepare color-tunable germanate phosphors BYGO:Dy3+,Sm3+. Under 365 nm excitation, the energy transfer-induced tunable emission of Dy3+/Sm3+ co-doped phosphors are investigated. The energy transfer mechanism is ascribed to the quadrupole-quadrupole interaction. The thermal quenching investigation manifests that the BYGO:Dy3+,Sm3+ phosphor has excellent thermostability (the emission intensity at 423 K reduces only 6.9 %) and resistance to chromaticity shifting (the chromaticity shifting parameter at 473 K is as low as 3.94 x 10(-3)). Meanwhile, the similar to 365 nm InGaN chip-excited w-LED device is fabricated with commercial phosphor BaSi2O2N2:Eu2+ and the title material, showing satisfactory electroluminescence performance. This work reveals that the title phosphor is a suitable candidate for solid-state lighting.