Great emission enhancement of high-efficient broadband K3YSi2O7: Eu red phosphor via enhancing crystallinity

Authors：Zhou, Weiying; Sun, Zishan; Luo, Jiabao; Zhang, Xinguo^*; Pang, Qi; Zhou, Liya

Source：Journal of Alloys and Compounds, 2021, 854: 157188.

DOI：10.1016/j.jallcom.2020.157188

• Red phosphor
• K3YSi2O7: Eu
• Crystallinity improvement
• Emission enhancement

Doping with alkali metal ions is an effective and universal method for luminescent efficiency enhancement of phosphors, but the corresponding mechanism of improvement remains ambiguous. This study presents a systematic investigation toward K+ excess-doped K3YSi2O7: Eu orange-emitting phosphor, whose emission intensity could reach to 200% enhancement over stoichiometric K+ sample. Analysis of X-ray diffraction, steady-state and dynamic fluorescence spectroscopies indicate that luminescent enhancement led by optimized K+ doping was mainly attributed to crystallinity enhancement. The optimized-composition phosphor, K3YSi2O7: Eu (140% K), shows improved emission thermal stability (60% of RT value at 200 degrees C) as well as enhanced internal quantum efficiency of 74.58% compared with 34.58% of stoichiometric K+ sample. As-fabricated white LED prototype exhibits excellent color quality (R-a = 92.2) along with low color temperature (CCT = 3089 K). The results indicate that the promising properties of the K3YSi2O7: Eu (140% K) red phosphor can ensure the better luminous performance of white LEDs.

• Institution
  南方医科大学; 广西大学