Cu掺杂天然方钠石的VUV-Vis发光特性

采用高温固相法制备了Cu掺杂天然方钠石光致发光粉末。使用电子探针能谱分析（EDS）和微区分析（EPMA）测出了天然方钠石所含的主要化学成分。用X射线衍射（XRD）研究了Cu掺杂对方钠石结构的影响。室温下测量了真空紫外-紫外-可见光光谱。结果表明，激发光谱中171 nm处的激发带属于基质吸收；202，255，280，290 nm左右的激发带是Cu⁺离子的3d¹⁰→3d⁹4s跃迁引起的。Cu在方钠石晶体中以两种位置存在，分别为Cu⁺离子在Na⁺离子晶格位置上出现的Cu1位置和复合层间的Cu2位置，并形成Cu⁺ 离子的Cu1和Cu2发光中心。用不同波长光激发Cu1和Cu2发光中心得到的峰值分别位于420 nm和470 nm的蓝色荧光来源于Cu⁺离子内的3d⁹4s→3d¹⁰电子跃迁。对样品的发光机理及浓度猝灭过程进行了探讨和研究。

Luminescence Properties of Cu Doped Natural Sodalite Under Ultraviolet-Vis Excitation

Cu doped natural sodalite phosphors were synthesized by solid-state reaction method at high-temperature. To examine chemical components of sodalite, we conducted electron probe micro-analysis (EPMA) and energy dispersive spectroscopy (EDS) analiysis using an electron probe scanning electron microscope spectrometer. The structure of Cu doped sodalite samples were characterized with X-ray diffraction (XRD). The VUV-Vis luminescence properties were measured at room temperature. The results show that the excitation band at 171 nm attributed to host absorption and that at 202, 255, 280, 290 nm are due to the 3d¹⁰→3d⁹4s transition of Cu⁺ ion. Cu existed in two lattice sites in the sodalite crystal, including Cu1 at the lattice site of Na⁺ ions and Cu2 between the composite layers, and formed Cu1 and Cu2 luminescence center of Cu⁺ ion, respectively. These emission spectra with the blue-ray peak at 420 nm and 470 nm, which were obtained by exciting the Cu1 and Cu2 luminescence center under different wavelength, and can be attributed to the 3d⁹4s→3d¹⁰ electronic transition of Cu⁺ ion. The mechanism of luminescence and concentration quenching process were discussed.