Trions, charged excitons that are reminiscent of hydrogen and positronium ions, have been intensively studied for energy harvesting, light-emitting diodes, lasing, and quantum computing applications because of their inherent connection with electron spin and dark excitons. However, these quasi-particles are typically present as a minority species at room temperature making it difficult for quantitative experimental measurements. Here, we show that by chemically engineering the well depth of sp³ quantum defects through a series of alkyl functional groups covalently attached to semiconducting carbon nanotube hosts, trions can be efficiently generated and localized at the trapping chemical defects. The exciton-electron binding energy of the trapped trion approaches 119 meV, which more than doubles that of “free” trions in the same host material (54 meV) and other nanoscale systems (2–45 meV). Magnetoluminescence spectroscopy suggests the absence of dark states in the energetic vicinity of trapped trions. Unexpectedly, the trapped trions are approximately 7.3-fold brighter than the brightest previously reported and 16 times as bright as native nanotube excitons, with a photoluminescence lifetime that is more than 100 times larger than that of free trions. These intriguing observations are understood by an efficient conversion of dark excitons to bright trions at the defect sites. This work makes trions synthetically accessible and uncovers the rich photophysics of these tricarrier quasi-particles, which may find broad implications in bioimaging, chemical sensing, energy harvesting, and light emitting in the short-wave infrared.

中文翻译：

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在化学定制的陷印缺陷中探测Trions。

由于其与电子自旋和暗态激子的内在联系，人们已经广泛地研究了Trions，它们是带电荷的激子，可激发氢和正电子离子，可用于能量收集，发光二极管，激光和量子计算应用。但是，这些准粒子在室温下通常以少数形式存在，因此难以进行定量实验测量。在这里，我们显示了通过化学工程对sp ^3的井深通过一系列共价连接到半导体碳纳米管主体上的烷基官能团产生的量子缺陷，可以有效地产生三重子并将其定位在捕获的化学缺陷处。被俘获的Trion的激子与电子的结合能接近119 meV，是同一基质材料（54 meV）和其他纳米级系统（2-45 meV）中“自由”三极子的两倍以上。磁致发光光谱法表明，在捕获的三子的高能区附近没有暗态。出乎意料的是，被捕获的tri子比以前报道的最亮的亮子大约亮7.3倍，是天然纳米管激子的16倍，其光致发光寿命比游离tri子大100倍以上。通过在缺陷部位将暗激子有效转换为亮sites，可以理解这些有趣的发现。这项工作使三核子可合成获得，并揭示了这些三载体类准粒子的丰富光物理性质，这可能在生物成像，化学传感，能量收集和短波红外光的发射中具有广泛的意义。