College of Chemistry, Chemical Engineering and Materials Science, Soochow University , Suzhou, Jiangsu 215123, China.
Inorg Chem. 2013 Sep 16;52(18):10407-13. doi: 10.1021/ic401854r. Epub 2013 Aug 26.
Niobates CaRNb3O10 (R = La, Sm, Eu, Gd, Dy, Er, Yb, or Y) were prepared by conventional high-temperature solid-state reaction. The formation of a single-phase compound with triple-layered perovskite-type structure was verified through X-ray diffraction (XRD) studies. The luminescence characteristics such as photoluminescence excitation and emission spectra, X-ray-excited luminescence (XEL), Stokes shift, decay curves, and color coordinates were investigated. The niobates can be efficiently excited by UV light and present luminescence behaviors with rich luminescence colors. Under excitation by ultraviolet radiation, CaRNb3O10 (R = La, Gd, Yb, or Y) exhibits strong blue luminescence due to the self-activation center of the octahedral NbO6 groups, even at room temperature. For the materials of composition CaRNb3O10 (R = Sm, Eu, Dy, or Er), the excitation at the host band produces a characteristic luminescence of rare earth ions, indicating a host-guest energy transfer process. CaRNb3O10 (R = Eu) has the strongest luminescence intensity, which can be efficiently excitated by near UV wavelength. It could be suggested to be a potential candidate for the application on near-UV excited white LEDs.
钙铌酸盐（CaRNb3O10，R = La、Sm、Eu、Gd、Dy、Er、Yb 或 Y）采用传统高温固相反应法制备。通过 X 射线衍射（XRD）研究证实了具有三层钙钛矿型结构的单相化合物的形成。研究了发光特性，如光致发光激发和发射光谱、X 射线激发发光（XEL）、Stokes 位移、衰减曲线和颜色坐标。这些铌酸盐可以被紫外光有效地激发，并呈现出丰富的发光颜色的发光行为。在紫外辐射激发下，由于八面体 NbO6 基团的自激活中心，即使在室温下，CaRNb3O10（R = La、Gd、Yb 或 Y）也表现出强烈的蓝色发光。对于组成 CaRNb3O10（R = Sm、Eu、Dy 或 Er）的材料，在主带激发下产生了稀土离子的特征发光，表明存在主客体能量传递过程。CaRNb3O10（R = Eu）具有最强的发光强度，可以被近紫外波长有效地激发。可以认为它是应用于近紫外激发白光 LED 的潜在候选材料。
