红色长余辉荧光粉Ca_2Zn_4Ti_(16)O_(38)∶Pr^(3+)的水热辅助合成及发光性质

Hydrothermal Assisted Synthesis and Photoluminescence Properties of Red Persistent Ca_2Zn_4Ti_(16)O_(38)∶Pr^(3+) Phosphor

采用水热法辅助合成了纯相Ca2Zn4Ti16O38∶Pr3+荧光粉,初始nCa∶nZn∶nTi=2∶4.1∶15,煅烧条件为1 050℃空气气氛烧结5 h。并以X射线衍射、扫描电镜、紫外可见漫反射光谱和荧光光谱表征了样品的物相组成、微观形貌和光谱性质。合成的荧光粉在高温煅烧后仍较好地保持了球形的微观形态,优化的Pr3+掺杂浓度为0.015。Ca2Zn4Ti16O38∶Pr3+荧光粉在471 nm波长激发下发射红光,发射谱通过高斯分峰拟合得到位于605、620和645 nm的3个发射峰,分别对应于Pr3+的1D2→3H4,3P0→3H6和3P0→3F2跃迁。在471 nm波长激发下,Ca2Zn4Ti16O38∶Pr3+的614 nm红光发射表现出超长余辉特性,表明该荧光粉是一种能被可见光有效激发的红色长余辉荧光粉。

Pure Ca2Zn4Ti16O38：Pr^3＋ phosphors were synthesized by a hydrothermal assisted method with the molar ratio of nCa：nZn：nTi being 2：4.1：15 and then calcined at 1 050 ℃ for 5 h. Crystal phase, microstmcture and optical properties were investigated by X-ray diffractometer, scanning electron microscope, UV-Vis spectroscope and luminescence spectrofluorometer. As-synthetic phosphors retain sphere even though firing at 1 050 ℃ for 5 h. The optimum Pr^3＋ concentration was 0.015. Upon excitation with 471 nm, the red emission spectra can be fitting into three peaks using Gaussian method. The three emission peaks located at 605, 620 and 645 nm can be ascribed to 1D2→3H4, 3P0→3H6 and 3P0→3F2 transition of Pr^3＋, respectively. It is noted that excited at 471 nm, the phosphor displays a super-long afterglow with the emission peak at 614 nm, indicating it being a persistent red long phosphor for visible-light conversion.