不同烧蚀条件下飞秒激光脉冲诱导ZnO纳米结构研究

烧蚀条件对飞秒激光脉冲诱导氧化锌纳米结构有重要影响。研究了800nm,150fs,250kHz的飞秒激光脉冲分别在空气中,去离子水中以及无水乙醇中垂直聚焦于氧化锌晶体表面,诱导形成不同形态的纳米结构。实验结果表明,在空气中利用飞秒激光脉冲辐照样品表面,形成了周期为180nm的纳米线;在去离子水中辐照诱导形成了由氧化锌纳米线聚集而成的"纳米球";在无水乙醇中形成出现分叉结构的纳米线。拉曼光谱分析辐照前后晶体晶相结果表明,形成的纳米结构相对于辐照前特征峰437cm-1强度有所下降,在570cm-1处的峰值则显著增强。分析了在各种烧蚀条件下诱导形成纳米结构的演化过程以及物理机理。

Ablation conditions play an important role in the femtosecond laser pulses induced nanostructures on ZnO. When 800 nm. 150 fs, 250 kHz femtosecond laser pulses were focused on the surface of ZnO in air, distilled water and ethanol, different nanostructures were produced. Experimental results show that femtosecond laser pulses induce nanowires with period of 180 nm in air, nanoballs constituted by ZnO nanowires are formed in distilled water, and obvious bifurcations are found in the nanostructures induced in ethanol. The results of Raman spectra indicate that the intensity of the fingerprint peak at 437 cm^-1 declines after the irradiation, and the peak at 570 cm^-1 is enhanced greatly. Surface nano-structuring evaluations and physical mechanisms under different conditions are analyzed in detail.