The introduction of sp³ defects into single-walled carbon nanotubes through covalent functionalization can generate new light-emitting states and thus dramatically expand their optical functionality. This may open up routes to enhanced imaging, photon upconversion, and room-temperature single-photon emission at telecom wavelengths. However, a significant challenge in harnessing this potential is that the nominally simple reaction chemistry of nanotube functionalization introduces a broad diversity of emitting states. Precisely defining a narrow band of emission energies necessitates constraining these states, which requires extreme selectivity in molecular binding configuration on the nanotube surface. We show here that such selectivity can be obtained through aryl functionalization of so-called ‘zigzag’ nanotube structures to achieve a threefold narrowing in emission bandwidth. Accompanying density functional theory modelling reveals that, because of the associated structural symmetry, the defect states become degenerate, thus limiting emission energies to a single narrow band. We show that this behaviour can only result from a predominant selectivity for ortho binding configurations of the aryl groups on the nanotube lattice.

sp ³的介绍通过共价官能化作用进入单壁碳纳米管的缺陷可以产生新的发光态，从而极大地扩展了它们的光学功能。这可能会开辟通往增强成像，光子上转换和电信波长下室温单光子发射的途径。然而，利用这种潜力的一个重大挑战是纳米管官能化的名义上简单的反应化学会引入多种发光态。精确定义窄的发射能量带需要约束这些状态，这要求在纳米管表面上的分子结合构型具有极高的选择性。我们在这里表明，可以通过所谓的“之字形”纳米管结构的芳基官能化来实现这种选择性，以实现发射带宽三倍的缩小。伴随的密度泛函理论建模表明，由于相关的结构对称性，缺陷状态变得简并，因此将发射能量限制为单个窄带。我们表明，这种行为只能由对纳米管晶格上的芳基的邻位结合构型。