Determination of the Quantum Dot Band Gap Dependence on Particle Size from Optical Absorbance and Transmission Electron Microscopy Measurements
Determination of the Quantum Dot Band Gap Dependence on Particle Size from Optical Absorbance and Transmission Electron Microscopy Measurements
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DOI：
10.1021/nn303130d
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发表时间：
2012-10-01
期刊：
影响因子：
17.1
通讯作者：
Peukert, Wolfgang
中科院分区：
文献类型：
--
作者：
Segets, Doris;Lucas, J. Matthew;Peukert, Wolfgang
这项工作解决了从PbS和PbSe量子点（QD）的光学吸收光谱的任意形状的颗粒尺寸分布（PSD）的测定，以达到在一个大的尺寸范围内的带隙能量和颗粒尺寸之间的关系。使用一个修改后的算法，这是以前开发的ZnO，我们只采取大量的吸收数据从文献和匹配的PSD来自QD吸收光谱与那些从透射电子显微镜（TEM）图像分析，以达到在功能上的依赖性的带隙对颗粒尺寸。额外的样品大小完全从他们的吸收光谱与我们的算法显示出良好的协议与TEM结果。我们研究了透射电镜图像分析的参数，如阈值对最终结果的影响。从两个样品的分析中得出的带隙与尺寸的关系在许多已发表的数据集的范围内。我们相信，我们的方法提供了一个有吸引力的捷径，研究各种新颖的量子限制的直接带隙半导体系统，因为它允许的带隙能量的宽尺寸范围的量子点进行探测与相对较少的合成实验，没有量子力学模拟。
This work addresses the determination of arbitrarily shaped particle size distributions (PSDs) from PbS and PbSe quantum dot (QD) optical absorbance spectra in order to arrive at a relationship between band gap energy and particle size over a large size range. Using a modified algorithm which was previously developed for ZnO, we take only bulk absorption data from the literature and match the PSDs derived from QD absorbance spectra with those from transmission electron microscopical (TEM) image analysis in order to arrive at the functional dependence of the band gap on particle size. Additional samples sized solely from their absorbance spectra with our algorithm show excellent agreement with TEM results. We investigate the influence of parameters of the TEM image analysis such as threshold value on the final result. The band gap versus size relationship developed from analysis of just two samples lies well within the bounds of a number of published data sets. We believe that our methodology provides an attractive shortcut for the study of various novel quantum-confined direct band gap semiconductor systems as it permits the band gap energies of a broad size range of QDs to be probed with relatively few synthetic experiments and without quantum mechanical simulations.