Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time
Femtosecond laser-induced size reduction of carbon nanodots in solution: Effect of laser fluence, spot size, and irradiation time
复制标题
飞秒激光诱导溶液中碳纳米点尺寸减小：激光能量密度、光斑尺寸和照射时间的影响
DOI：
10.1063/1.4909506
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发表时间：
2015-02-28
影响因子：
3.2
通讯作者：
Hou, Xun
中科院分区：
文献类型：
--
作者：
Vanthan Nguyen;Yan, Lihe;Hou, Xun
采用飞秒激光烧蚀法在聚乙二醇（PEG 200 N）溶液中制备了尺寸可调且均匀的光致发光碳纳米点（C点）。通过调节激光能量密度、光斑尺寸和照射时间等参数，可以很好地控制C点的尺寸分布和光致发光（PL）特性。随着激光能量密度和光斑尺寸的减小，C点的尺寸减小效率逐渐增加。随着C点尺寸的增大，最佳PL谱发生红移，量子产率降低，这可能是由于在较高的激光能量密度和较大的光斑尺寸下，C点表面形成了更为复杂的表面官能团。随着辐照时间的增加，C点的尺寸减小，但长时间的辐照会导致C点上产生复杂的官能团，从而使PL谱发生红移。
Photoluminescent carbon nanodots (C-dots) with size tunability and uniformity were fabricated in polyethylene glycol (PEG200N) solution using femtosecond laser ablation method. The size distributions and photoluminescence (PL) properties of C-dots are well controlled by adjusting the combined parameters of laser fluence, spot size, and irradiation time. The size reduction efficiency of the C-dots progressively increases with decreasing laser fluence and spot size. The optimal PL spectra are red-shifted and the quantum yields decrease with the increase in C-dots size, which could be attributed to the more complex surface functional groups attached on C-dots induced at higher laser fluence and larger spot size. Moreover, an increase in irradiation time leads to a decrease in size of C-dots, but long-time irradiation will result in the generation of complex functional groups on C-dots, subsequently the PL spectra are red-shifted.