Langhammer Christoph, Schwind Markus, Kasemo Bengt, Zorić Igor
Department of Applied Physics, Chalmers University of Technology, 412 96 Göteborg, Sweden.
Nano Lett. 2008 May;8(5):1461-71. doi: 10.1021/nl080453i. Epub 2008 Apr 5.
The plasmonic properties of arrays of supported Al nanodisks, fabricated by hole-mask colloidal lithography (HCL), are analyzed for the disk diameter range 61-492 nm at a constant disk height of 20 nm. Strong and well-defined (UV-vis-NIR) localized surface plasmon resonances are found and experimentally characterized with respect to spectral peak positions, peak widths, total cross sections, and radiative and nonradiative decay channels. Theoretically, the plasmon excitations are described by electrostatic spheroid theory. Very good qualitative and quantitative agreement between model and experiment is found for all these observables by assuming a nanoparticle embedded in a few nanometer thick homogeneous (native) aluminum oxide shell. Other addressed aspects are: (i) the role of the strong interband transition in Al metal, located at 1.5 eV, for the plasmonic excitations of Al nanoparticles, (ii) the role of the native oxide layer, and (iii) the possibility of using the plasmon excitation as an ultrasensitive, remote, real-time probe for studies of oxidation/corrosion kinetics in metal nanoparticle systems.
通过孔掩膜胶体光刻技术（HCL）制备的负载型铝纳米盘阵列的等离子体特性，在盘高恒定为20nm的情况下，针对61 - 492nm的盘直径范围进行了分析。发现了强烈且明确的（紫外 - 可见 - 近红外）局域表面等离子体共振，并就光谱峰值位置、峰宽、总截面以及辐射和非辐射衰减通道进行了实验表征。从理论上讲，等离子体激发由静电椭球体理论描述。通过假设纳米颗粒嵌入几纳米厚的均匀（天然）氧化铝壳层，在所有这些可观测量方面，模型与实验之间发现了非常好的定性和定量一致性。其他涉及的方面包括：（i）位于1.5eV的铝金属中强带间跃迁对铝纳米颗粒等离子体激发的作用，（ii）天然氧化层的作用，以及（iii）将等离子体激发用作超灵敏、远程、实时探针来研究金属纳米颗粒系统中氧化/腐蚀动力学的可能性。
