Hexagonal structured YPO₄:Tb/Sm (h-YPO₄:Tb/Sm) nanorods with significantly large aspect ratios of up to ∼32 have been successfully fabricated via hydrothermal crystallization in the presence of sodium malate (Mal²⁻) and superfluous PO₄³⁻. The combined techniques of XRD, SEM, TEM, and PLE/PL were employed to characterize the products, and the formation mechanism of the nanorods was discussed in detail. It was found that Mal²⁻ and superfluous PO₄³⁻ jointly ensured the crystallization of the metastable hexagonal phase, and the latter promoted the 1D growth of the crystals. The h-(Y_0.99−xTb_0.01Sm_x)PO₄ ternary phosphors simultaneously displayed the green emission of Tb³⁺ at 545 nm and the red emission of Sm³⁺ at 601 nm under 221 nm UV excitation, with which the emission color was finely tuned from green to yellow by increasing the Sm³⁺ content. The Tb³⁺ → Sm³⁺ energy transfer in h-(Y_0.99−xTb_0.01Sm_x)PO₄ was revealed to occur via an electric dipole–dipole interaction mechanism. The fluorescence lifetime of Tb³⁺ was found to steadily decrease with increasing Sm³⁺ concentration, and the efficiency of energy transfer was determined to be ∼31.2% at the optimal Sm³⁺ content of 4 at% (x = 0.04).

中文翻译：

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六方结构YPO ₄：Sm / Tb纳米棒的增强水热结晶和可定制颜色的光致发光†

在苹果酸钠（Mal ^2-）和多余的PO存在下，通过水热结晶成功制备了纵横比大至高达约32的六方结构YPO ₄：Tb / Sm（h-YPO ₄：Tb / Sm）纳米棒。₄ ³⁻。结合XRD，SEM，TEM和PLE / PL技术对产物进行表征，详细讨论了纳米棒的形成机理。发现Mal ²⁻和多余的PO ₄ ³⁻共同确保了亚稳六方相的结晶，而后者促进了晶体的一维生长。h-（Y _{0.99− x} Tb_0.01 Sm _x）PO ₄三元荧光粉在221 nm UV激发下同时显示545 nm处的Tb ³⁺的绿色发射和601 nm处的Sm ³⁺的红色发射，其发射颜色通过绿色从微调为黄色。增加Sm ³⁺含量。发现在h-（Y _{0.99− x} Tb _0.01 Sm _x）PO ₄中的Tb ³⁺ →Sm ³⁺能量转移是通过电偶极-偶极相互作用机理发生的。发现Tb ³⁺的荧光寿命随着Sm的增加而稳定下降³⁺浓度，并且在4 at％的最佳Sm ³⁺含量下，能量转移的效率确定为〜31.2％（ x = 0.04）。