After coating NaYbF 4 shell on the 20Yb/2Er: NaGdF 4 core nanocrystals, upconversion emission intensity decreased. Through acore@shell@shell sandwich like structure, we find that high Yb 3+ concentration in the shell has mainly two adverse impacts: it promotes not only the deleterious back-energy- ...
Cr 3+ doped transparent glassceramics of SiO 2 -Ga 2 O 3 -Li 2 O werefabricated by melt-quenching and subsequent crystallization. X-ray diffractionand transmission electron microscopy analyses evidenced that cubic LiGa 5 O 8 nanocrystals were homogeneously precipitated among the silicate ...
Currently, upconversion nanocrystals and long-lasting phosphorescent particles have attracted extensive research interests for their possible applications as bio-imaging probes. However, there are few reports concerning the achievement of both upconversion luminescence of lanthanide ions an ...
A NIR long persistent Cr 3+ : SrGa 12 O 19 phosphor with persistent time lasting formore than 2 h has been successfully fabricated.The doped Cr 3+ ions prefer to occupy the octahedral sites of Ga 3+ with the intermediate crystal field strength. The NIR LPP can be effectively realized by UV ...
Monodisperse Pr 3+ /Yb 3+ :NaGdF 4 @NaYF 4 active-core/inert-shell nanoparticles, whichexhibit efficient near-infrared quantum cutting luminescence, are successfullyprepared. In order to relieve the adverse effect caused by concentration quenching in the core, the extra Yb 3+ ions are ...
The purpose of the present work is to demonstrate that the hexagonal Yb/Er:NaGdF4core size has a great impact on the completeness of the NaYF4 shell coveringthe core. With the increase of core size, the morphology of core–shell nanocrystals evolves from nanosphere to hexagonal nanoprism and fi ...
目前国际上主流的白光 LED 器件是将 Ce : YAG 荧光粉分散在环氧树脂或硅胶中然后再涂敷在蓝光芯片上所构成。环氧树脂或硅胶在大功率芯片产生的高温环境下,容易发生老化,颜色变黄,使得 LED 产生色偏和光衰,缩短了其使用寿命。因此,研发光学性能优越、物化稳定性高的新型荧光材料来代替 Ce : YAG/ 有机基质荧光体 ...