Sm3+-doped LnNbO4 (Ln=La, Y) phosphors were obtained by high-temperature solid-state reaction. The crystal structure of LnNbO4:Sm3+ (Ln=La, Y) was characterized by X-ray diffraction. Luminescent properties of those phosphors were investigated by diffuse reflection spectra, excitation spectra, as well as emission spectra. The emission spectra of those phosphors consisted of several orangish-red emission bands around 550–670 nm upon the excitation at 405 nm, and the luminescent emission intensity of LaNbO4: Sm3+ was much stronger than that of YNbO4: Sm3+. The 87.0% energy transfer efficiency from the host to Sm3+ ions was observed in LaNbO4: Sm3+ phosphor. Furthermore, the critical transfer distance was calculated and the CIE chromaticity coordinates of LaNbO4: Sm3+ samples were in the range of orangish-red. The fluorescence lifetimes of as-prepared LaNbO4: Sm3+ samples were within the millisecond range and the temperature-dependent luminescence indicated LaNbO4: Sm3+ was highly thermal-stable. Our results indicated that novel orangish-red-emitting LnNbO4: Sm3+ (Ln=La, Y) phosphors were expected to have great potential in white LEDs.

中文翻译：

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新型热稳定橙红色发光 LnNbO4: Sm3+ (Ln=La, Y) 荧光粉的合成和发光性能

Sm3+掺杂的LnNbO4 (Ln=La, Y)荧光粉是通过高温固相反应获得的。LnNbO4:Sm3+ (Ln=La, Y) 的晶体结构通过 X 射线衍射表征。通过漫反射光谱、激发光谱以及发射光谱研究了这些磷光体的发光特性。在 405 nm 激发后，这些荧光粉的发射光谱由 550-670 nm 附近的几个橙红色发射带组成，LaNbO4:Sm3+ 的发光强度比 YNbO4:Sm3+ 强得多。在 LaNbO4: Sm3+ 磷光体中观察到从主体到 Sm3+ 离子的 87.0% 能量转移效率。此外，计算了临界转移距离，LaNbO4: Sm3+ 样品的 CIE 色度坐标在橙红色范围内。所制备的 LaNbO4: Sm3+ 样品的荧光寿命在毫秒范围内，并且随温度变化的发光表明 LaNbO4: Sm3+ 具有高度的热稳定性。我们的结果表明，新型橙红色发光 LnNbO4: Sm3+ (Ln=La, Y) 荧光粉有望在白光 LED 中具有巨大潜力。