Abstract Niobate phosphors (ANbO4; A: Y, Gd, La) are fascinating wide-bandgap materials which attracts vast interest and vital applications. These compounds exhibit fergusonite crystal structure and give broad-band self-activated emission due to ligand to metal charge transfer band from O2- to Nb5+ ions. Presence of Bi3+ in ANbO4 creates low lying new states (due to metal to metal charge transfer state of Bi3+ to Nb5+ ions) and changes crystal field, which enhances overall intensity of the self-activated luminescence. The self-activated emission of ANbO4 sensitizes dopant ions in them, particularly trivalent lanthanides, which emanate luminescence in different spectral region and open enormous application for this host. Aim of this review is to pinpoint suitable synthesis technique of ANbO4 phosphor, highlight the current understanding of their crystal structure and optical behavior, and to discourse their vital technological applications. A concise summary and prospective is also covered to signpost the future research directions.

中文翻译：

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宽带隙镧系铌酸盐：光学特性和应用

摘要 铌酸盐荧光粉 (ANbO4; A: Y, Gd, La) 是一种引人入胜的宽带隙材料，吸引了广泛的兴趣和重要的应用。由于配体到金属电荷转移带从 O2- 到 Nb5+ 离子，这些化合物表现出铁格石晶体结构并产生宽带自激活发射。ANbO4 中 Bi3+ 的存在产生了低位的新状态（由于 Bi3+ 到 Nb5+ 离子的金属到金属电荷转移状态）并改变了晶体场，从而增强了自激活发光的整体强度。ANbO4 的自激活发射使其中的掺杂离子变得敏感，特别是三价镧系元素，它们在不同的光谱区域发出发光，并为该宿主开辟了巨大的应用前景。本综述的目的是确定合适的 ANbO4 荧光粉合成技术，突出当前对其晶体结构和光学行为的理解，并讨论其重要的技术应用。还涵盖了简明的总结和展望，以指明未来的研究方向。