A novel Mn⁴⁺-doped Li₄Mg₂TaO₆F oxyfluoride phosphor was synthesized via a scalable environmentally benign high-temperature solid-state reaction route. Introducing NaF as a charge compensator effectively suppressed the formation of cation vacancies induced by Mn⁴⁺→Ta⁵⁺ heterovalent substitution, resulting in substantial enhancement of far-red luminescence. Specifically, an optimized phosphor with 25% NaF demonstrated remarkable 112% increase in emission intensity at 672 nm and exhibited a two-fold improvement in internal quantum efficiency from 17% to 34%. The synthesized phosphor features an ultra-broad emission band spanning from 625 to 830 nm, closely matching the absorption spectrum of plant phytochrome P_FR absorption (660 nm), thus highlighting its strong potential for precision agricultural lighting. A prototype phosphor-converted LED, fabricated by coupling the phosphor with a 450 nm blue-emitting LED chip, exhibited stable radiant flux and consistent emission characteristics across a wide range of driving currents (30-300 mA). Although further improvement in thermal stability (T_0.5 ≈ 360 K) remains necessary, this work establishes an effective defect engineering paradigm for designing high-performance, eco-friendly Mn⁴⁺-doped phosphors specifically tailored for advanced agricultural lighting.

中文翻译：

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通过 NaF 电荷补偿在 Mn4 +掺杂的 Li4Mg2TaO6F 氧氟化物荧光粉中进行宽带远红农业照明的缺陷工程

通过可扩展的环境良性高温固相反应路线合成了一种新型 Mn⁴⁺ 掺杂的 Li₄Mg₂TaO₆F 氟氧氟化物荧光粉。引入 NaF 作为电荷补偿剂有效抑制了 Mn⁴⁺→Ta⁵⁺ 异价取代诱导的阳离子空位的形成，导致远红外发光的显着增强。具体来说，含有 25% NaF 的优化荧光粉在 672 nm 处的发射强度显着提高了 112%，内部量子效率提高了两倍，从 17% 提高到 34%。合成的荧光粉具有 625 至 830 nm 的超宽发射带，与植物植物色素 P_FR 吸收光谱 （660 nm） 紧密匹配，从而凸显了其在精确农业照明方面的巨大潜力。通过将荧光粉与 450 nm 蓝光发光 LED 芯片耦合而制造的荧光粉转换 LED 原型在很宽的驱动电流范围 （30-300 mA） 下表现出稳定的辐射通量和一致的发射特性。尽管还需要进一步提高热稳定性 （T_0.5 ≈ 360 K），但这项工作为设计专为先进农业照明量身定制的高性能、环保型 Mn⁴⁺ 掺杂荧光粉建立了有效的缺陷工程范式。