Sebastian Finn L, Zorn Nicolas F, Settele Simon, Lindenthal Sebastian, Berger Felix J, Bendel Christoph, Li Han, Flavel Benjamin S, Zaumseil Jana
Institute for Physical Chemistry, Universität Heidelberg, D-69120 Heidelberg, Germany.
Institute of Nanotechnology, Karlsruhe Institute of Technology, D-76131 Karlsruhe, Germany.
J Phys Chem Lett. 2022 Apr 28;13(16):3542-3548. doi: 10.1021/acs.jpclett.2c00758. Epub 2022 Apr 14.
The functionalization of semiconducting single-wall carbon nanotubes (SWCNTs) with luminescent sp defects creates red-shifted emission features in the near-infrared and boosts their photoluminescence quantum yields (PLQYs). While multiple synthetic routes for the selective introduction of sp defects have been developed, a convenient metric to precisely quantify the number of defects on a SWCNT lattice is not available. Here, we present a direct and simple quantification protocol based on a linear correlation of the integrated Raman D/G signal ratios and defect densities as extracted from PLQY measurements. Corroborated by a statistical analysis of single-nanotube emission spectra at cryogenic temperature, this method enables the quantitative evaluation of sp defect densities in (6,5) SWCNTs with an error of ±3 defects per micrometer and the determination of oscillator strengths for different defect types. The developed protocol requires only standard Raman spectroscopy and is independent of the defect configuration, dispersion solvent, and nanotube length.
用发光的sp缺陷对半导体单壁碳纳米管（SWCNT）进行功能化处理，可在近红外区域产生红移发射特征，并提高其光致发光量子产率（PLQY）。虽然已经开发出多种选择性引入sp缺陷的合成路线，但尚无一种方便的指标来精确量化SWCNT晶格上的缺陷数量。在此，我们基于从PLQY测量中提取的积分拉曼D/G信号比与缺陷密度的线性相关性，提出了一种直接且简单的量化方案。通过对低温下单纳米管发射光谱的统计分析得到证实，该方法能够定量评估（6,5）SWCNT中的sp缺陷密度，误差为每微米±3个缺陷，并能确定不同缺陷类型的振子强度。所开发的方案仅需标准拉曼光谱，且与缺陷构型、分散溶剂和纳米管长度无关。
