Department of Chemistry, National Institute of Technology, Rourkela, Odisha - 769008, India.
Dalton Trans. 2021 Apr 14;50(14):4986-5000. doi: 10.1039/d1dt00449b. Epub 2021 Mar 26.
Narrow-band red-emitters are the key to solving problems encountered by the current white LED technology. In this context, a series of new red-emitting LiBaSrLa(MoO):Eu phosphors were synthesized and characterized through various spectroscopic methods. All phosphor compositions were crystallized in the monoclinic phase, with space group C2/c. A broad charge transfer (O→ Mo) extended up to the blue region along with strong F→L, D absorption, making them looked-for materials for warm white LED applications. The concentration quenching study reveals that there was no concentration-quenching occuring and the quantum yield of this non-concentration-quenching LiBaSrLaEu(MoO) phosphor reaches 92.6%. The LiBaSrLaEu(MoO) retain >80% of its emission intensity at 150 °C. The best red-emitting composition was integrated with near UV LED and obtained bright red emission with CIE x = 0.6647, y = 0.3357. White LED was fabricated by integrating the blue LED with yellow dye + red phosphor and white LED showed bright white light with CCT (5546 K), CIE (0.331, 0.385), and CRI (81%). In addition, the red LED spectrum is well-matched with the phytochrome (Pr) absorption spectrum and is useful for plant growth applications.
窄带红色发射体是解决当前白光 LED 技术所遇到问题的关键。在此背景下，我们通过各种光谱方法合成并表征了一系列新型红色发射 LiBaSrLa(MoO):Eu 荧光粉。所有荧光粉组成均结晶为单斜相，空间群为 C2/c。宽的电荷转移（O→Mo）扩展到蓝色区域，同时具有强的 F→L、D 吸收，使它们成为暖白光 LED 应用的理想材料。浓度猝灭研究表明，没有浓度猝灭现象发生，且这种非浓度猝灭的 LiBaSrLaEu(MoO)荧光粉的量子产率达到 92.6%。LiBaSrLaEu(MoO)在 150°C 时仍保留>80%的发射强度。最佳红色发射组成与近紫外 LED 集成，获得了 CIE x = 0.6647、y = 0.3357 的明亮红色发射。通过将蓝色 LED 与黄色染料+红色荧光粉集成，制备了白光 LED，白光 LED 呈现出 CCT（5546 K）、CIE（0.331、0.385）和 CRI（81%）的明亮白光。此外，红色 LED 光谱与光敏色素（Pr）吸收光谱很好地匹配，对植物生长应用有用。
