On the absorption cross section of CdSe nanocrystal quantum dots
On the absorption cross section of CdSe nanocrystal quantum dots
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DOI：
10.1021/jp025698c
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发表时间：
2002-08-08
影响因子：
3.3
通讯作者：
Bawendi, MG
中科院分区：
文献类型：
--
作者：
Leatherdale, CA;Woo, WK;Bawendi, MG
线性吸收截面是纳米晶体量子点器件设计和光谱数据解释的重要参数。我们测量并报告了CdSe纳米晶体量子点的尺寸依赖吸收截面。我们将远高于带边缘的吸收结果与吸收光的小颗粒的光散射的简单理论模型进行了比较，在那里量子点密度的状态可以近似为连续体。正己烷中的稀分散体与理论非常吻合。我们发现，对于350 nm的吸收，CdSe的每粒子吸收截面C-abs（单位cm(2)）为C-abs = (5.501 x 10(5))a(3) cm(-1)，其中a为粒子半径，单位cm。观察到吸收截面对溶剂折射率基本不敏感。为了理解纳米晶体量子点的吸收特性对介质折射率缺乏敏感性，可能有必要对配体壳的影响进行详细的建模。
The linear absorption cross section is a crucial parameter to the design of nanocrystal quantum dot devices and to the interpretation of spectroscopic data. We measure and report the size-dependent absorption cross section of CdSe nanocrystal quantum dots. We compare the results for absorption far above the band edge, where the quantum dot density of states may be approximated as a continuum, to simple theoretical models of light scattering from light-absorbing small particles. Excellent agreement with theory is found for dilute dispersions in hexane. We find that for absorption at 350 nm the per particle absorption cross section C-abs (in cm(2)) for CdSe is C-abs = (5.501 x 10(5))a(3) cm(-1), where a is the particle radius in cm. The absorption cross section is observed to be largely insensitive to the solvent refractive index. Detailed modeling of the effect of the ligand shell may be necessary to understand the lack of sensitivity of the absorption properties of nanocrystal quantum dots to the refractive index of the medium.