Zhao Ming, Xia Zhiguo, Huang Xiaoxiao, Ning Lixin, Gautier Romain, Molokeev Maxim S, Zhou Yayun, Chuang Yu-Chun, Zhang Qinyuan, Liu Quanlin, Poeppelmeier Kenneth R
The Beijing Municipal Key Laboratory of New Energy Materials and Technologies, School of Materials Sciences and Engineering, University of Science and Technology Beijing, Beijing 100083, China.
State Key Laboratory of Luminescent Materials and Devices and Institute of Optical Communication Materials, South China University of Technology, Guangzhou 510641, China.
Sci Adv. 2019 Jan 11;5(1):eaav0363. doi: 10.1126/sciadv.aav0363. eCollection 2019 Jan.
Solid-state phosphor-converted white light-emitting diodes (pc-WLEDs) are currently revolutionizing the lighting industry. To advance the technology, phosphors with high efficiency, tunable photoluminescence, and high thermal stability are required. Here, we demonstrate that a simple lithium incorporation in NaAlSiO:Eu system enables the simultaneous fulfillment of the three criteria. The Li substitution at Al sites beside Na sites in NaAlSiO:Eu leads to an enhanced emission intensity/efficiency owing to an effective Eu to Eu reduction, an emission color tuning from yellow to green by tuning the occupation of different Eu sites, and an improvement of luminescence thermal stability as a result of the interplay with Li-related defects. A pc-WLED using the Li-codoped NaAlSiO:Eu as a green component exhibits improved performance. The phosphors with multiple activator sites can facilitate the positive synergistic effect on luminescence properties.
固态磷光体转换白光发光二极管（pc-WLED）目前正在彻底改变照明行业。为了推动该技术发展，需要具有高效率、可调谐光致发光和高热稳定性的磷光体。在此，我们证明在NaAlSiO:Eu体系中简单引入锂能够同时满足这三个标准。在NaAlSiO:Eu中，Li取代Na位点旁边的Al位点，由于有效的Eu-Eu还原，导致发射强度/效率增强；通过调整不同Eu位点的占据情况，发射颜色从黄色调至绿色；并且由于与Li相关缺陷的相互作用，发光热稳定性得到改善。使用锂共掺杂的NaAlSiO:Eu作为绿色组分的pc-WLED表现出更好的性能。具有多个激活剂位点的磷光体可以促进对发光性能产生积极的协同效应。
