Li Jiayu, Wuenschell Jeffrey, Li Zhuo, Bera Subhabrata, Liu Kai, Tang Renhong, Du Henry, Ohodnicki Paul R, Shen Sheng
Department of Mechanical Engineering, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
National Energy Technology Laboratory, 626 Cochrans Mill Road, Pittsburgh, PA, 15236, USA.
Small. 2021 Apr;17(17):e2007274. doi: 10.1002/smll.202007274. Epub 2021 Mar 14.
Nanostructured gold has attracted significant interest from materials science, chemistry, optics and photonics, and biology due to their extraordinary potential for manipulating visible and near-infrared light through the excitation of plasmon resonances. However, gold nanostructures are rarely measured experimentally in their plasmonic properties and hardly used for high-temperature applications because of the inherent instability in mass and shape due to the high surface energy at elevated temperatures. In this work, the first direct observation of thermally excited surface plasmons in gold nanorods at 1100 K is demonstrated. By coupling with an optical fiber in the near-field, the thermally excited surface plasmons from gold nanorods can be converted into the propagating modes in the optical fiber and experimentally characterized in a remote manner. This fiber-coupled technique can effectively characterize the near-field thermoplasmonic emission from gold nanorods. A direct simulation scheme is also developed to quantitively understand the thermal emission from the array of gold nanorods. The experimental work in conjunction with the direct simulation results paves the way of using gold nanostructures as high-temperature plasmonic nanomaterials, which has important implications in thermal energy conversion, thermal emission control, and chemical sensing.
纳米结构金因其通过激发等离子体共振来操纵可见光和近红外光的非凡潜力，已引起材料科学、化学、光学与光子学以及生物学领域的广泛关注。然而，由于高温下高表面能导致的质量和形状固有不稳定性，金纳米结构很少通过实验测量其等离子体特性，并且几乎不用于高温应用。在这项工作中，首次展示了在1100 K下对金纳米棒中热激发表面等离子体的直接观测。通过在近场与光纤耦合，金纳米棒的热激发表面等离子体可转换为光纤中的传播模式，并以远程方式进行实验表征。这种光纤耦合技术能够有效表征金纳米棒的近场热等离子体发射。还开发了一种直接模拟方案，以定量理解金纳米棒阵列的热发射。结合实验工作与直接模拟结果，为将金纳米结构用作高温等离子体纳米材料铺平了道路，这在热能转换、热发射控制和化学传感方面具有重要意义。
