Ultrashort-pulse laser ablation of gold thin film targets: Theory and experiment
Ultrashort-pulse laser ablation of gold thin film targets: Theory and experiment
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DOI：
10.1016/j.tsf.2013.10.165
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发表时间：
2014-01-01
期刊：
影响因子：
2.1
通讯作者：
Atanasov, P. A.
中科院分区：
文献类型：
--
作者：
Amoruso, S.;Nedyalkov, N. N.;Atanasov, P. A.
采用分子动力学模拟方法研究了超短脉冲激光烧蚀金薄膜的过程，并与体靶的烧蚀过程进行了比较。被认为是一个膜厚度的弹道电子深度在金（约100 nm），证明了一个显着的变化的温度空间分布内的目标材料，这最终影响材料的分解。特别强调的是纳米粒子的生成过程。模拟表明，在薄膜的情况下，样品的加热更均匀，这伴随着烧蚀过程中产生的纳米颗粒的尺寸分布更均匀。还进行了超短脉冲烧蚀过程的实验表征。将产生的纳米颗粒收集在合适的基底上，并对少于一层的沉积物进行原子力显微镜分析。在金薄膜烧蚀的情况下，观察到相当于球形直径尺寸分布的纳米颗粒的近似2倍变窄，与理论预测相当吻合。此外，有趣的变化的纳米粒子的形状被证明，这是相关的纳米粒子烧蚀羽流动力学的变化，研究其自发射的时间选通成像。我们的研究结果表明，超短脉冲激光烧蚀薄膜作为一种可行的途径，以实现更均匀的纳米颗粒尺寸分布。(C)2013 Elsevier B.V.保留所有权利。
Laser ablation of a gold thin film irradiated by ultrashort pulses is studied using molecular-dynamics simulations, and compared with that of a bulk target. A film thickness comparable to the ballistic electron depth in gold (approximate to 100 nm) is considered, evidencing a significant change of the temperature spatial profile inside the target material, which eventually influences the material decomposition. Particular emphasis is given to the process of nanoparticle generation. The simulations indicate a more uniform heating of the sample in the case of the thin film, which is accompanied by a more homogeneous size distribution of the nanoparticles produced in the ablation process. An experimental characterization of the ultrashort-pulse ablation process is also carried out. The produced nanoparticles are collected on suitable substrates, and atomic force microscopy analysis of less than one layer deposits is performed. An approximate to 2x narrowing of the nanoparticles equivalent to spherical diameter size distribution is observed in the case of ablation of the gold thin film, in fairly good agreement with the theoretical predictions. Moreover, interesting changes of the nanoparticle shape are evidenced, which are correlated to the changes in the nanoparticle ablation plume dynamics, as studied by time-gated imaging of its self-emission. Our findings suggest ultrashort-pulse laser ablation of thin films as a viable route to achieve a more uniform nanoparticle size distribution. (C) 2013 Elsevier B.V. All rights reserved.