摘要
含发光中心的纳米粒子在介质中随机分布,造成局域介质相对折射率的随机分布,导致了纳米粒子辐射寿命的涨落。分析纳米粒子数量在线度为发射光波长量级的体积内的概率密度,由此得出局域介质相对折射率的概率密度。通过纳米粒子辐射寿命对折射率的依赖关系,得到纳米粒子辐射寿命概率密度的解析表达。在此基础上,分析了Meltzer等人的实验中,含Eu3+离子的Y2O3粒子在甲醇溶液中辐射寿命的相对偏移量的涨落,并得出辐射寿命的不确定度(均方差)与纳米粒子体积、体积密度等物理量的关系。
Spontaneous emission rate is not only affected by the properties of the material itself, but also depends on the dielectric properties of the surrounding media. Recently, some work has been carried out to study the dependence of sporitaneous emission rates of the luminescent-ion-containing nanometer particles on the refractive index of the media. Based on the free distribution of nanometer particles in media, the probability density of luminescent lifetime is analyzed.
Since nanometer particles distribute freely in media, the number of nanometer particles in a given volume surrounding the luminescent center obeys the Poission distribution. The local relative refractive index nr, which is the ratio of media effective refractive index to particle refractive index, is affected by the particle number of nanoparticles within a sphere of radius half of the radiative wavelength. The probab function of nr can be obtained according to the dependence of nr on the particle number. Based on between nr and luminescence is obtained. lifetime, the analytical form of ility density the relation probability density function of lifetime is obtained.
A calculation has been done based on the parameters given in Meltzer＇s experiment （Eu^3＋ doped Y2O3 in methanol）. The result shows that the relative fluctuation of luminescence lifetime is too small to be observed.
出处
《发光学报》
EI
CAS
CSCD
北大核心
2007年第3期313-316,共4页
Chinese Journal of Luminescence
基金
教育部重点计划(205133
KJ05O514)
重庆邮电学院青年基金(A2005-16)资助项目
关键词
纳米粒子
折射率
辐射寿命
辐射寿命相对偏移量
均方差
nanometer particle
luminescent lifetime
local-field effect
refractive index
mean squaredeviation
