Optomechanics of Single Aluminum Nanodisks
Optomechanics of Single Aluminum Nanodisks
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DOI：
10.1021/acs.nanolett.7b00333
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发表时间：
2017-04-01
期刊：
影响因子：
10.8
通讯作者：
Link, Stephan
中科院分区：
文献类型：
--
作者：
Su, Man-Nung;Dongare, Pratiksha D.;Link, Stephan
铝纳米结构支持可调谐表面等离子体共振，并已成为金纳米粒子的替代品。金是研究最多的等离子体材料，而铝则具有地球丰度高、成本低的优势。除了了解等离子共振的尺寸和形状可调性之外，还必须了解光激发后铝纳米结构的基本弛豫过程，以充分利用光催化和光电检测等应用。在这项工作中，我们使用单粒子瞬态消光光谱研究了超快脉冲激发后的弛豫以及单个铝纳米盘中声振动的发射。我们发现瞬态消光信号可以归因于光激发电子和声子的热弛豫。超快加热引起的面内声振动的发射揭示了与玻璃基板的适度结合，并受到天然氧化铝层的影响。最后，我们将铝纳米盘的行为与类似制备和尺寸的金纳米盘的行为进行比较。
Aluminum nanostructures support tunable surface plasmon resonances and have become an alternative to gold nanopartides. Whereas gold is the most-studied plasmonic material, aluminum has the advantage of high earth abundance and hence low cost. In addition to understanding the size and shape tunability of the plasmon resonance, the fundamental relaxation processes in aluminum nanostructures after photoexcitation must be understood to take full advantage of applications such as photocatalysis and photodetection. In this work, we investigate the relaxation following ultrafast pulsed excitation and the launching of acoustic vibrations in individual aluminum nanodisks, using single-particle transient extinction spectroscopy. We find that the transient extinction signal can be assigned to a thermal relaxation of the photo excited electrons and phonons. The ultrafast heating-induced launching of in-plane acoustic vibrations reveals moderate binding to the glass substrate and is affected by the native aluminum oxide layer. Finally, we compare the behavior of aluminum nanodisks to that of similarly prepared and sized gold nanodisks.