如何测定荧光量子效率

如何测定荧光量子效率
首先要有一个已知量子产率的标准物质，一般用硫酸奎宁。

分别做标准物质和未知样品的吸收和荧光光谱。

Φu=Φs(Yu/Ys)(As/Au)
Φu——待求物质的荧光量子产率；
Φs——标准物质的荧光量子产率；
Yu——待求物质的荧光积分面积；
Ys——标准物质的荧光积分面积；
Au——待求物质的荧光激发波长处的吸收值；
As——标准物质的荧光激发波长处的吸收值。

测定激发光强度和荧光强度就可以了知道吧？
如果已知一标准物质的量子产率，可以配置相同浓度的标准和待测物质，在相同的测量条件下，测量两者的荧光强度.未知物质的荧光量子产率=F未知/F标准*标准的量子产率。

量子效率是指发射的光子数Nf与激发时吸收的光子数NX之比,即
量子效率=Nf/NX
我们知道,一般的发光总有一定的能量损失,激发光子的能量总是大于发射光子的能量.所以,量子效率通常都是小于100%.在实际测量时我们不好去测量发射的光子数Nf与激发时吸收的光子数NX,而通常用用下面的公式求算:
量子效率=发射峰的最大发光强度/激发峰的最大发光强度
但是注意根据待测物的激发和发射波长的范围，选择不同激发和发射波长的基准物。

请问在有机电致发光中
关于量子效率中的外量子效率是如何计算的
公式是什么样子的
exp(eV/kT)=aP2+bP+c(1)
其中V为光生电压，k为玻尔兹曼常数，T为绝对温度，e为电子电荷，a，b，c 为常数。

Additionally,α-NPN thin film emits bright blue fluorescence(461 nm) 1.
-NPD(5.5%). efficiency of 8.5%,higher than that of αwith a quantum该化合物可发明亮的蓝色荧光(461 nm),积分球测定其薄膜荧光量子效率为8.5%,比α-NPD 的5.5%高。

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emission properties were studied and their photolysis
Their fluorescence2.kinetics was investigated in
different media by means of steady state
photolysis method.较低，光谱特性，发现甲氧基苯甲酰亚甲基光产碱剂的荧光量子效率考察了其荧光而萘甲酰亚甲基光产碱剂较高。

收藏指正of oxazine 1 perohlorate in 1, 2-efficiency quantum The fluorescence3.
dichloro-ethane was measured with photoacoustic speetroscopy in which
the fluorescence quenching wag used.荧光高氯酸盐的二氯乙烷溶液进行)嗪1利用光声光谱技术,采取猝灭的方法对(口恶收藏指正量子效率的测量。

for the
efficiencyquantum The experimental results indicate that the 4.
μm than that at 0.80 μm, emission at 1.5 μm is higher upon excitation at 0.98owing to the much weaker excited state absorption (ESA) compared with
those of excitation at 0.80 μm. 因而其激发下小得多, ,激发态吸收较0 .80μm研究表明:由于在0 .98μm激发下;收藏指正也比0 .80μm激发下高得多荧光1.5μm发射量子效率-property of coumarin derivative CND_(500) with βFluorescence5.-CD) in aqueous solution and CND_(500) with ethyl alcohol, cyclodextrin (βmethod. It n-saf Triton X-100 micelle solution are examined by fluorescence fluorescence is observed that the peak, relative intensity (F), polarization
(P), relative quantum yield ((?)
用荧光法研究了香豆素衍生物CND_(500)在β-CD水溶液中和在乙醇及非离子表面活性剂(n-Saf)Triton X-100等胶束溶液中的荧光特性,发现CND_(500)在β-CD水溶液中的荧光强度(F),荧光偏振度(P)、相对量子效率((?)收藏指正
Abstract: Polyphenylacetylenes were synthesized by ［Rn(nbd)Cl］2 and 6.WCl6/Ph4Sn catalyst systems in N2 at room temperature.Polymers
with
high yield and high molecular weight were obtained.Their structures were
characterized by UV,IR,NMR and GPC,respectively.The fluorescence of the
polymer solution with different concentration was investigated using variable excitation wavelength from UV to visible region.The relation between fluorescence and polymer structure was studied.The results
showed that the molecular chain structure has great influence on fluorescence of the polymers.The emitting peak wavelength of
fluorescence for the polymer of high stereoregularity is independent of
solution concentration and excitation wavelength.The emitting peak wavelength of fluorescence for the polymer with disordered molecular
chain arrangement varies with changing the solution concentration and excitation wavelength,and different emission sites in molecular chains and
low emitting yield are shown.The measurement and analysis of fluorescence spectroscopy of polyphenylacetylenes may provide some
useful information to judge the molecular chain arrangement in some
conjugated polymers.
文摘:使用有机金属铑、金属钨/四苯基锡催化剂体系聚合苯乙炔，分别获得了高产等分别对聚合物结构进行了GPC，NMR，IR，UV使用.率和高分子量的聚苯乙炔．
表征.采用不同波长的激发光对聚合物荧光性能进行研究，详细分析了聚合物结构与荧光性能之间的关系.研究结果发现，不同聚合物结构对聚合物荧光性能产生很大影响，规整性高的聚合物，将有较高的发光量子效率；聚合物规整性差，将可能导致多个荧光发光结构点，其荧光强度降低.聚合物荧光光谱研究将对某些共轭聚合物结构的规整性分析提供一些有用的信息.收藏指正
The rate constant and the efficiency of main energy trasfer process were 7.calculated from fluorescence lifetime, phosphorescence lifetime,quantum
yield and time-resolved spectra of I3MK and I3MK-Tb(Ⅲ)stsyem. Accordingly,the dynamics of the energy-transfer process in this system was analysed. A modification of the perrin formula was proposed and the mechanism of the energy transfer of the complex system was disscussed.
从I3MK和I3MK－Tb（Ⅲ）体系的荧光寿命、磷光寿命、量子产率，时间分辨光谱等，计算了各主要能量传递过程的速率常数和能量传递效率，进行了该体系能量传递过程的动态分析，提出了Perrin公式的修正参数，讨论了I3MK－Tb（Ⅲ）体系的能量传递机理．收藏指正
The results showed that with the increasing water
8.stress,Fv/Fm,Fv/Fo,Yield,qP and Photo values decreased,while
qN,which
reflects the protective mechanism of light energy,increased significantly.
研究结果表明,叶片的叶绿素荧光参数PSII原初光能转换效率(Fv/Fm)、PSII潜在活性(Fv/Fo)、光合量子产额(Yield)、光化学淬灭系数(qP)和净光合速率(Photo)值随水分胁迫强度增强而呈下降的趋势;收藏指正
Either of the two stresses increased minimum chlorophyll
9.florescence(F0),and decreased maximum chlorophyll
fluorescence(Fm),PSⅡprimary chemical
efficiency(Fv/Fm)and PSⅡpotential activity(Fv/F0),but
did not significantly result in variation in quantum yield of PSⅡlinear
electron(ΦPSⅡ) relative to the un-stressed control. POD activity,MDA and
Pro contents were significantly raised by drought or salinity.
干旱或盐胁迫引起初始荧光(F0)上升,最大荧光(Fm)、PSⅡ原初光能转化效率
(Fv/Fm)和PSⅡ潜在活性(Fv/F0)显著下降,PSⅡ实际光化学量子产量(ΦPSⅡ)略有降低,而POD活性、MDA和Pro含量显著提高。

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The results showed that the diurnal variation of PS II primarily chemical 10.efficiency (Fv/Fm), quantum yield of PS II linear electron(OPS II) and
estimated electron transport rate (ETR) in 6 rice varieties related to light
intensity.
进一步系统研究上述品种在孕穗期连体倒二叶片功能叶)的荧光参数的日变化，并解析了它们与耐光氧化和耐荫特性的关系。

结果表明：6个水稻品种叶片的原初光化学效率(Fv／Fm)，实际光化学量子产量(φPSⅡ)和通过PSⅡ的电子传递速率(ETR)的日变化与光强有关。

荧光粉及荧光量子效率检测系统
The above picture shows a system for determining the quantum efficiency of phosphor powder samples used in the lighting industry.
Up to 6 samples can be loaded into the motorised carousel. A calibrated Hg source, with closed loop controller for necessary stability, is used to excite the phosphors. Significantly, the oo C all under 1temperature of each sample can be heated to 200C ±software control.
A carefully designed integrating sphere is used to collect all of the
emitted light which is measured by a spectroradiometer system. Besides quantum efficiency of the phosphors and function of operating temperature, the system also provides full spectral emission and chromaticity data.
荧光量子效率的测定
分类:有机合成
2007.9.16 00:54 作者：过路庄子| 评论：1 | 阅读：619
物质吸光跃迁至激发态后,可能会发生荧光发射、内转移，系间窜跃和外转移等过程,也就是说,荧光发射只是多个竞争过程中的一个,因此,需要引入荧光量子效率的.概念来衡量物质荧光发射的能力
定义: 荧光量子效率=发射荧光分子数 / 激发分子总数
目前测定荧光量子效率最通用的是所谓Optically Dilute Measurements(The Journalof Phyaical Chemisty,76, 8,1971,991-1024):通常会选取一个已知荧光量子效率的标准样品,比如二苯蒽和硫酸喹啉.二苯蒽的环己烷溶液在370nm 左右激发量子效率为0.9.下边的例子就是以二苯蒽的环己烷溶液为标样的.
计算公式:
其中,Qr为标样已知的量子效率.Ar和Ax分别为标样和待测样在激发波长处的吸收值.I为激发波长出的入射强度,因为通常标样和待测样的测试条件完全一样,因为他们的比值为1,这一项可以略去.nx和nr分别为待测样和标样所用溶剂的折射率.Dx和Dr分别是待测样和标样的发射谱积分面积.
(1) 测定待测样品的吸收和发射,以便选择合适的标样以及激发波长.标样选择有两个条件必须满足:一是待测样品与标样的吸收波长范围尽量重叠;二是激发波长要位于二苯蒽及待测物发射谱之外,否则发射峰不能出全,积分后的面积不能很好的代表荧光发射的实际能力.
(2) 根据朗伯-比尔定律,稀释标样及样品的浓度至他们在激发波长附近的吸收值落在0.05-0.1之间, 两者的吸收值越接近越好,有的人干脆就选取他们吸收曲线交点处的波长为激发波长,那么吸收值之比一项就为1了,当然即使是曲线交点处为激发波长,也要位于最大吸收波长附近.
(3) 在同等条件下(激发波长,狭缝宽度,扫描范围,衰减与否)扫出标样和待测样品的发射谱,并利用仪器自带软件计算发射谱的积分面积.
将上述各个参数代入公式中,就得到了荧光量子效率.
下边给出我最近的一个例子,虚线表示激发波长的选取.。