Zhou Jianbang, Wang Yunfeng, Chen Yingyuan, Zhou Yayun, Milićević Bojana, Zhou Lei, Yan Jing, Shi Jianxin, Liu Ru-Shi, Wu Mingmei
School of Marine Sciences/and School of Chemistry, Sun Yat-Sen University, Zhuhai 519082, Guangzhou, 510275, P. R. China.
School of Electronics and Electrical Engineering, Nanyang Institute of Technology, Nanyang, 473004, P. R. China.
Angew Chem Int Ed Engl. 2021 Feb 19;60(8):3940-3945. doi: 10.1002/anie.202011022. Epub 2020 Dec 28.
A solvent-vapor transport route produces centimeter-sized single-crystal red phosphors. The epitaxial growth route to yield its core-shell structure at ambient temperature was adopted. These red phosphors could be applied in all-inorganic WLED devices. Cs TiF :Mn (CTFM) single crystal provides enhancement of quantum efficiency, moisture resistance, and thermal stability compared to polycrystalline powders. The internal quantum efficiency can reach as high as 98.7 %. To further improve waterproof stability, the Cs TiF (CTF) shell with tunable thickness has been epitaxially grown on the CTFM single crystal surface and a unique three-step photoluminescence intensity evolution mechanism has been proposed. By combining as-prepared CTFM@CTF core-shell structured single crystal, YAG:Ce single crystal and blue-chip, warm WLEDs with excellent color rendition (R =90, R =94), low correlated color temperature (CCT=3155 K), and high luminous efficacy were fabricated without any organic resins.
溶剂蒸汽传输路线可制备出厘米级的单晶红色荧光粉。采用了在室温下外延生长以形成其核壳结构的路线。这些红色荧光粉可应用于全无机白光发光二极管（WLED）器件中。与多晶粉末相比，CsTiF:Mn（CTFM）单晶具有更高的量子效率、防潮性和热稳定性。其内部量子效率可高达98.7%。为进一步提高防水稳定性，已在CTFM单晶表面外延生长了厚度可调的CsTiF（CTF）壳层，并提出了一种独特的三步光致发光强度演变机制。通过将制备好的CTFM@CTF核壳结构单晶、YAG:Ce单晶和蓝色芯片相结合，制备出了具有出色显色指数（Ra=90，R94）、低相关色温（CCT=3155 K）和高发光效率的暖白光WLED，且未使用任何有机树脂。
