基于能量传递的 Ba_(3)Y_(2)(BO_(3))_(4):Yb^(3+)/Er^(3+)颜色可调上转换发光研究

采用高温固相法合成了不同Yb^(3+)掺杂量的新型Ba_(3)Y_(2)(BO_(3))_(4):Yb^(3+)/Er^(3+)上转换荧光粉。借助XRD、SEM、荧光光谱等表征方法研究了Yb^(3+)掺杂量对材料晶体结构、上转换发光性能的影响,探讨了材料的上转换发光机制。结果表明,Yb^(3+)、Er^(3+)的掺杂未引入杂相,由于Yb^(3+)、Er^(3+)与Y^(3+)离子半径相近,随着Yb^(3+)掺杂量增加,晶胞参数呈现微弱的减小趋势。Yb^(3+)掺杂量0.05时,荧光粉具有最大发光强度。调控Yb^(3+)掺杂量,增强了Yb^(3+)与Er^(3+)间的能量传递,实现了样品发光颜色由绿色→黄色→红色的转变。在980 nm激光激发下,Er^(3+)的绿光和红光发射均为双光子过程。

X-Ray Diffraction Pattern of Graphite Oxide

X-ray diffraction patterns of graphite oxide(GO)are theoretically simulated as a function of the displacements of carbon atoms using the Debye–Waller factor in terms of the Warren–Bodenstein equation.The results demon-strate that GO has the turbostratically stacked structure.The high order(001)peaks gradually disappear with the increase in atomic thermal vibrations along𝑑c-axis while the(ℎk0)ones weaken for the vibrations along a-axis.When the displacement deviation𝑣ua𝑏=0.015nm and𝑣𝑑uc=0.100nm the computed result is consistent with the experimental measurements.