Ye Menglin, Yang Chen, Wang Aolin, Chen Gengli, Yuan Dongming, Zhou Wenli
Key Laboratory of Light Energy Conversion Materials of Hunan Province College, Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research (Ministry of Education of China), College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, China.
Inorg Chem. 2023 Jul 31;62(30):12130-12137. doi: 10.1021/acs.inorgchem.3c01709. Epub 2023 Jul 17.
Mn-activated fluoride red phosphors exhibit excellent luminescence properties. However, a persistent technical challenge lies in their poor moisture resistance. Current strategies primarily focus on surface modifications to effectively shield the [MnF] species from water molecules while neglecting the underlying structure of the fluoride matrix. In this study, we introduce Si and Ge ions into the KTiF:Mn crystal to create covalent fluoride solid solutions, namely, KTiSiF:Mn and KTiGeF:Mn, through crystal reconstruction. The findings reveal that the incorporation of Si leads to increased particle size, enhanced luminescence intensity (by 40%), and improved moisture resistance. Furthermore, after undergoing 1000 h of aging at high temperature and high humidity conditions, the white LED featuring the KTiSiF:Mn phosphor demonstrates remarkable durability by retaining 90% of its initial luminous efficacy. This performance surpasses that of the device utilizing the KTiF:Mn phosphor, which only retains 74% of its original efficacy. The crystal reconstruction method and covalent enhancement strategy proposed in this work contribute to enhancing the luminescence efficiency and moisture resistance of fluoride phosphors, thereby offering new insights for advancing the development of high-efficiency and highly stable white light LED devices.
锰激活的氟化物红色磷光体具有优异的发光性能。然而，一个长期存在的技术挑战在于它们的耐湿性较差。目前的策略主要集中在表面改性上，以有效地保护[MnF]物种免受水分子的影响，而忽略了氟化物基质的潜在结构。在本研究中，我们通过晶体重构将Si和Ge离子引入KTiF:Mn晶体中，以创建共价氟化物固溶体，即KTiSiF:Mn和KTiGeF:Mn。研究结果表明，Si的掺入导致粒径增大、发光强度增强（提高了40%）以及耐湿性改善。此外，在高温高湿条件下经过1000小时的老化后，采用KTiSiF:Mn磷光体的白光发光二极管表现出显著的耐久性，保留了其初始发光效率的9 >0%。这种性能超过了使用KTiF:Mn磷光体的器件，后者仅保留了其原始效率的74%。本工作中提出的晶体重构方法和共价增强策略有助于提高氟化物磷光体的发光效率和耐湿性，从而为推进高效、高稳定性白光发光二极管器件的发展提供了新的见解。
