Wang Shaoying, Sun Qi, Devakumar Balaji, Sun Liangling, Liang Jia, Huang Xiaoyong
Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, College of Physics and Optoelectronics, Taiyuan University of Technology Taiyuan 030024 P. R. China
RSC Adv. 2018 Aug 28;8(53):30191-30200. doi: 10.1039/c8ra06134c. eCollection 2018 Aug 24.
Novel Mn-activated far-red emitting SrMgLaWO (SMLW) phosphors were prepared by a conventional high-temperature solid-state reaction method. The SMLW:Mn phosphors showed a broad excitation band peaking at around 344 nm and 469 nm in the range of 300-550 nm. Under 344 nm near-ultraviolet light or 469 nm blue light, the phosphors exhibited a far-red emission band in the 650-780 nm range centered at about 708 nm. The optimal Mn doping concentration in the SMLW host was 0.2 mol% and the CIE chromaticity coordinates of SMLW:0.2% Mn phosphors were calculated to be (0.7322, 0.2678). In addition, the influences of crystal field strength and nephelauxetic effect on the emission energy of Mn ions were also investigated. Moreover, the internal quantum efficiency of SMLW:0.2% Mn phosphors reached as high as 88% and they also possessed good thermal stability. Specifically, the emission intensity at 423 K still maintained about 57.5% of the initial value at 303 K. Finally, a far-red light-emitting diode (LED) lamp was fabricated by using a 365 nm near-ultraviolet emitting LED chip combined with the as-obtained SMLW:0.2% Mn far-red phosphors.
采用传统高温固相反应法制备了新型Mn激活的远红光发射SrMgLaWO（SMLW）荧光粉。SMLW:Mn荧光粉在300 - 550 nm范围内呈现出分别在344 nm和469 nm左右有峰值的宽激发带。在344 nm近紫外光或469 nm蓝光激发下，荧光粉在650 - 780 nm范围内呈现出以约708 nm为中心的远红光发射带。SMLW基质中Mn的最佳掺杂浓度为0.2 mol%，计算得出SMLW:0.2% Mn荧光粉的CIE色度坐标为(0.7322, 0.2678)。此外，还研究了晶体场强度和电子云扩张效应对Mn离子发射能量的影响。而且，SMLW:0.2% Mn荧光粉的内量子效率高达88%，并且具有良好的热稳定性。具体而言，在423 K时的发射强度仍保持在303 K时初始值的约57.5%。最后，通过将365 nm近紫外发光LED芯片与所制备的SMLW:0.2% Mn远红光荧光粉相结合，制作了一个远红光发光二极管（LED）灯。
