Improved photoluminescence intensity and thermal stability brought by increasing Eu3+ content in KBaY1−xEuxSi2O7 solid-solution phosphors

Developing high brightness, high color purity and thermal stable red phosphors has gained an increasing attention for enhancing the performance of white light emitting diodes (w-LEDs). Herein, a series of red-emitting KBaY 1−x Eu x Si 2 O 7 (0 < x < 1) solid-solution phosphors were designed and fabricated. The phosphors can be excited by 394 nm near-UV light and emit red light peaking at 612 nm due to the 5 D 0  →  7 F 2 transition of Eu 3+ . The increasing proportion of Eu 3+ in the solid-solution system can improve the photoluminescence intensity and thermal stability of the phosphors continuously until the Eu 3+ concentration comes to 100%, while no deformation of the crystal structure has been brought. The as-prepared KBaEuSi 2 O 7 phosphor shows excellent thermal photoluminescence stability, its emission integrated intensity can still maintain ∼90% of the initial value at room temperature when heating to 180 °C. The CIE coordinates (0.652, 0.348) of KBaEuSi 2 O 7 phosphor are very close to the NTSC (National television system committee) standard red chromaticity (0.67, 0.33), and the color shift at high temperature is very slight. The KBaEuSi 2 O 7 phosphor can be regarded as a promising red luminescence candidate for w-LEDs.