标题： 如何识别单壁碳纳米管中发光缺陷的聚类 显示英文标题

标题： How to Recognize Clustering of Luminescent Defects in Single-Wall Carbon Nanotubes

摘要： 半导体单壁碳纳米管（SWCNTs）是一种有前景的材料平台，适用于近红外体内成像、光学传感和通信波长的单光子发射。 通过发光缺陷对SWCNTs进行功能化，由于高效捕获高迁移率激子以及这些陷阱态的红移发射，可以显著增强光致发光（PL）特性。 在研究最多的发光缺陷类型中，氧缺陷和芳基缺陷具有 largely 相似的光学特性。 到目前为止，尚未在相同条件下对功能化氧缺陷和芳基缺陷的SWCNTs进行直接比较。 在此，我们采用组合光谱技术来量化缺陷的数量、它们沿纳米管的分布以及因此它们的激子捕获效率。 从PL量子产率测量计算出的缺陷密度与拉曼D/G+比值的不同斜率表明氧缺陷和芳基缺陷之间存在显著差异。 通过对低温下单纳米管PL光谱的统计分析，揭示了氧缺陷的聚集。 2-3个氧缺陷的聚集，作为单一激子陷阱，无论功能化方法如何，都会发生，从而使得可以根据标准拉曼光谱法使用简单方程来确定SWCNTs中氧缺陷和氧缺陷簇的密度。 所提出的分析方法是一种多功能且灵敏的工具，用于研究SWCNTs中的缺陷分布和聚集，并可应用于任何新的功能化方法。 显示英文摘要

摘要： Semiconducting single-wall carbon nanotubes (SWCNTs) are a promising material platform for near-infrared in-vivo imaging, optical sensing, and single-photon emission at telecommunication wavelengths. The functionalization of SWCNTs with luminescent defects can lead to significantly enhanced photoluminescence (PL) properties due to efficient trapping of highly mobile excitons and red-shifted emission from these trap states. Among the most studied luminescent defect types are oxygen and aryl defects that have largely similar optical properties. So far, no direct comparison between SWCNTs functionalized with oxygen and aryl defects under identical conditions has been performed. Here, we employ a combination of spectroscopic techniques to quantify the number of defects, their distribution along the nanotubes and thus their exciton trapping efficiencies. The different slopes of Raman D/G+ ratios versus calculated defect densities from PL quantum yield measurements indicate substantial dissimilarities between oxygen and aryl defects. Supported by statistical analysis of single-nanotube PL spectra at cryogenic temperatures it reveals clustering of oxygen defects. The clustering of 2-3 oxygen defects, which act as a single exciton trap, occurs irrespective of the functionalization method and thus enables the use of simple equations to determine the density of oxygen defects and oxygen defect clusters in SWCNTs based on standard Raman spectroscopy. The presented analytical approach is a versatile and sensitive tool to study defect distribution and clustering in SWCNTs and can be applied to any new functionalization method.