General Physics Institute RAS, Vavilov Street 38, 119991 Moscow, Russia.
Institute of Physical Chemistry and Electrochemistry RAS, Leninsky pr. 31, 119071, Moscow, Russia.
Nat Nanotechnol. 2014 Jan;9(1):54-8. doi: 10.1038/nnano.2013.255. Epub 2013 Dec 8.
Doping of carbon nanoparticles with impurity atoms is central to their application. However, doping has proven elusive for very small carbon nanoparticles because of their limited availability and a lack of fundamental understanding of impurity stability in such nanostructures. Here, we show that isolated diamond nanoparticles as small as 1.6 nm, comprising only ∼400 carbon atoms, are capable of housing stable photoluminescent colour centres, namely the silicon vacancy (SiV). Surprisingly, fluorescence from SiVs is stable over time, and few or only single colour centres are found per nanocrystal. We also observe size-dependent SiV emission supported by quantum-chemical simulation of SiV energy levels in small nanodiamonds. Our work opens the way to investigating the physics and chemistry of molecular-sized cubic carbon clusters and promises the application of ultrasmall non-perturbative fluorescent nanoparticles as markers in microscopy and sensing.
杂质原子掺杂碳纳米粒子对其应用至关重要。然而，由于非常小的碳纳米粒子的可用性有限，以及对这种纳米结构中杂质稳定性的基本理解不足，掺杂一直难以实现。在这里，我们表明，小至 1.6nm、仅包含约 400 个碳原子的孤立金刚石纳米粒子能够容纳稳定的光致发光色心，即硅空位 (SiV)。令人惊讶的是，SiV 的荧光随时间保持稳定，并且每个纳米晶体中发现的 SiV 数量很少或只有一个。我们还观察到 SiV 发射与小纳米金刚石中 SiV 能级的量子化学模拟相支持的尺寸依赖性。我们的工作为研究分子大小的立方碳团簇的物理和化学开辟了道路，并有望将超小非微扰荧光纳米粒子作为显微镜和传感中的标记物应用。
