Boiko Vitalii, Dai Zhengfa, Chaika Mykhailo, Grzeszkiewicz Karina, Li Jiang, Strek Wieslaw, Hreniak Dariusz
Division of Optical Spectroscopy, Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okolna 2, PL 50-422 Wroclaw, Poland.
Key Laboratory of Transparent Opto-Functional Inorganic Materials, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201899, China.
Materials (Basel). 2022 Jun 22;15(13):4407. doi: 10.3390/ma15134407.
In the current work, YAGG:Cr nanophosphors were synthesized by the Pechini method and then annealed at different temperatures in the range 800-1300 °C. The structure and morphology of the samples were characterized by X-ray Powder Diffraction (XRPD). The lattice parameters and average crystalline sizes as site occupation by Al and Ga ions were calculated from the Rietveld refinement data. To investigate the effect of crystalline size of the materials on their optical properties: excitation and emission spectra were recorded and analyzed. Finally, the effect of crystalline size on the probability of carrier recombination leading to PersL was determined experimentally with thermoluminescence analyses. The T-T method was applied to determine the trap type and particle size (calcination temperature) effect on their redistribution. A correlation between structural changes and trap redistribution was found. In particular, the extinction of high-temperature TL maximum with increasing annealing temperatures is observed, while low-temperature TL maximum increases and reaches a maximum when the lattice parameter reaches saturation.
在当前工作中，采用佩琴尼法合成了YAGG:Cr纳米磷光体，然后在800 - 1300℃范围内的不同温度下进行退火处理。通过X射线粉末衍射（XRPD）对样品的结构和形貌进行了表征。根据Rietveld精修数据计算了晶格参数、平均晶体尺寸以及Al和Ga离子的占位情况。为了研究材料晶体尺寸对其光学性质的影响：记录并分析了激发光谱和发射光谱。最后，通过热释光分析实验确定了晶体尺寸对导致持久发光的载流子复合概率的影响。采用T - T方法确定陷阱类型以及粒径（煅烧温度）对其重新分布的影响。发现了结构变化与陷阱重新分布之间的相关性。特别是，观察到随着退火温度升高，高温热释光最大值消失，而低温热释光最大值增加，并在晶格参数达到饱和时达到最大值。
