相关实验视频
Updated: Jun 29, 2025

07:03
Low-energy Cathodoluminescence for OxyNitride Phosphors
Published on: November 15, 2016
10.7K
概括
与兰化物添加的升级转换 (UC) 材料,如Y2Mo4O15:Yb3+/Tm3+微晶,尽管是窄带,但显示出高效的UC发射. 这一发现挑战了以前的假设,并为先进的防伪应用打开了大门.
科学领域:
- 材料科学 材料科学 材料科学
- 光学是什么?光学是什么?光学是什么?
- 纳米技术纳米技术
背景情况:
- 用兰化物添加的升级转换 (UC) 材料将低能激发转化为高能排放.
- 之前认为高效的UC发光 (UCL) 需要宽带间隙材料.
- Y2Mo4O15:Yb3+/Tm3+微晶是具有独特光学特性的窄带材料.
研究的目的:
- 为了研究窄带Y2Mo4O15:Yb3+/Tm3+微晶中的上转换发光.
- 挑战有效的UCL仅限于宽带间隙材料的概念.
- 探索这些微晶在防伪和信息加密方面的潜力.
主要方法:
- 对Y2Mo4O15:Yb3+/Tm3+微晶体进行实验合成和表征.
- 对上转换发光的光谱分析.
- 理论计算以了解底层的光学机制.
- 将UCL强度与商业上转换光剂进行比较.
主要成果:
- 在窄带Y2Mo4O15:Yb3+/Tm3+微晶体中观察到高效的UC发射.
- 排放强度远远超过商业中使用的NaYF4:Yb3+,Er3+和NaYF4:Yb3+,Tm3+.
- 四和五光子UC发射波段的消失是由于强烈的宿主-辅助剂相互作用造成的.
结论:
- 窄带Y2Mo4O15:Yb3+/Tm3+微晶体表现出优越的UCL效率,与此前的看法相反.
- 观察到的现象与Y2Mo4O15带隙和Tm3+能量水平之间的相互作用有关.
- 这些微晶对于先进的防伪和信息加密技术具有前途.
相关概念视频
Photoluminescence: Fluorescence and Phosphorescence
2.0K
Photoluminescence is a process where a molecule absorbs light energy and re-emits it in the form of light. This phenomenon occurs when a substance absorbs photons, promoting its electrons to higher energy level excited states, followed by a relaxation process in which the electrons return to their original ground state energy levels and emit light. Photoluminescence is widely observed in various materials, including semiconductors, and organic and inorganic compounds.
A pair of electrons in a...
A pair of electrons in a...
2.0K
Photoluminescence: Applications
393
Photoluminescence offers a wide range of applications due to its inherent sensitivity and selectivity. This technique allows for both direct and indirect analyses of the analyte. Direct quantitative analysis is possible when the analyte exhibits a favorable quantum yield for fluorescence or phosphorescence. However, an indirect analysis may be feasible if the analyte is not fluorescent or phosphorescent, or if the quantum yield is unfavorable. Indirect methods include reacting the analyte with...
393
Super-resolution Fluorescence Microscopy
7.0K
Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been...
7.0K

