Role of oxygen vacancy in rare-earth-free LiCa3Mg(VO4)3 phosphor:Enhancing photoluminescence by heat-treatment in oxygen flow

• 作者: Yixuan Lv Yijun Zhang Le Shi Jian-Wen Shi Jun Li Zhihui Li Xin Ji Dandan Ma Yonghong Cheng Chunming Niu
• 来源期刊: 材料科学技术（英文版）
• 年，卷（期）: 2021,（20）
• 页码范围: 123-132
• 页数: 10页
• 语种: 英文

摘要

As a kind of white light emitting diode (w-LED) with many advantages,rare-earth-free vanadate phosphor has attracted more and more attention.The oxygen vacancies and other surface defects in vanadate oxide have obvious effects on its structure and properties.In order to reveal the specific effects,we heat-treat the original LiCa3Mg(VO4)3 (LCMV) in an oxygen flow with different time to decrease oxygen vacancies,and find that the lattice distortion of[VO4]tetrahedron caused by oxygen vacancy is effectively reduced.Meanwhile,the crystallinity of the treated samples increases,the surface defects decreases,and the fluorescence intensity increases.The variation of photoluminescence quantum yield (PLQY) with oxygen treatment time is as follows:the enhancement effect firstly reaches the strongest (69.34 ％) within one hour,then begins to decline after two hours,and finally reaches the platform after three hours and remains basically unchanged.The reason for the enhancement of PLQY is the decrease of oxygen vacancy after one-hour treatment,and the reason for the decrease of PLQY after a further increased treatment time is that the absorption of oxygen and water in air caused by excessive surface defects introduced by oxygen treatment.