In the study, well-crystallized nano-diamonds with an average size of 3.8 nm are obtained via femtosecond laser ablation. Both steady-state and transient luminescence are observed. The luminescence peaks of nano-diamonds shift from 380 to 495 nm when the excitation wavelength changes from 280 to 420 nm. After passivation by polyethylene glycol-400N, the surface of nano-diamonds is significantly oxidized, which is verified by Raman and UV-Vis absorption spectra. Furthermore, there is no change in all the luminescence wavelengths, although the maximum intensity increases by 10 times. Time-resolved luminescence spectra reveal that trapping states can be modified by surface passivation, and this leads to stronger luminescence with a longer lifetime.

在这项研究中，通过飞秒激光烧蚀获得了平均结晶度为3.8 nm的结晶良好的纳米金刚石。观察到稳态和瞬态发光。当激发波长从280 nm变为420 nm时，纳米金刚石的发光峰从380 nm变为495 nm。通过聚乙二醇400N钝化后，纳米金刚石的表面被显着氧化，这通过拉曼光谱和UV-Vis吸收光谱进行了验证。此外，尽管最大强度增加了10倍，但所有发光波长都没有变化。时间分辨的发光光谱表明，俘获态可以通过表面钝化来改变，这导致更强的发光和更长的寿命。