| Submitter: |
Helmut Coelfen |
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| Authors: |
Eva Peters,Rose Rosenberg, Klaus Boldt∗, and Helmut Cölfen,∗
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| Corresponding Author: |
Eva Peters,Rose Rosenberg, Klaus Boldt∗, and Helmut Cölfen,∗ |
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| Title: |
Analysis of Magic-Size Nanocrystals in Crude Reaction Mixtures Using Multiwavelength Analytical Ultracentrifugation |
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| Contribution Type: |
Full Talk |
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| Selected for Presentation |
Yes |
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| Abstract: |
Magic-size clusters are ultrasmall, transient species that appear early during semi- conductor nanocrystal growth and have been assigned to stoichiometrically and geo- metrically well-defined structures. Yet, a direct analysis has proved difficult due to their limited stability and challenging isolation. Analytical ultracentrifugation is a promising tool to analyze these compounds, because it circumvents the need to purify, and thereby destabilize, the clusters while yielding information of their sedimentation and diffusion behavior, size, shape and composition. We employ a multi-wavelength detector that allows the detection of whole absorption spectra during centrifugation to separate and identify individual magic-size clusters in crude reaction mixtures sampled directly from the colloidal syntheses. Analytical ultracentrifugation thus constitutes an elegant, independent high-resolution and statistically significant method to show the step-wise growth of magic-size clusters, confirming recent growth models. |
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