标题： 增强三维多孔金天线的红外能量传输 显示英文标题

标题： Boosting infrared energy transfer in 3D nanoporous gold antennas

摘要： 等离子体学在将自由空间辐射能量传递给分子方面的应用目前仅限于电磁光谱的可见区域，这是由于块状贵金属固有的光学特性，它们只能在可见/紫外范围内的等离子体频率附近支持强电磁场约束。 在本工作中，我们表明纳米多孔金可以作为中红外区域的等离子体材料，以实现强电磁场约束，与目标分子共定位在纳米孔中，并与其振动频率共振。 纳米多孔金属的有效光学响应使得光场能够深入渗透到纳米孔中，其中可以装载分子，从而相比块状金，实现了更高效的光-物质耦合。 为了实现由纳米多孔金制成的等离子体谐振器，我们开发了一种基于聚合物模板的金属沉积纳米制造方法，并获得了在中红外波长下共振的天线阵列，这些波长通过设计选择。 然后，我们将天线涂上一层薄（3 nm）的二氧化硅层，作为光学能量转移的目标介电层。 我们通过分析实验中的法诺线型来研究二氧化硅在1250 cm-1振动吸收频率处的光-物质耦合强度，并将其与由块状金制成的相同结构进行对比。 从自由空间中红外辐射到纳米多孔三维纳米天线阵列中分子振动的光学能量传递增强，可能会为等离子体增强的物理化学反应开辟新的应用途径。 显示英文摘要

摘要： The applications of plasmonics to energy transfer from free-space radiation to molecules are currently limited to the visible region of the electromagnetic spectrum due to the intrinsic optical properties of bulk noble metals that support strong electromagnetic field confinement only close to their plasma frequency in the visible/ultraviolet range. In this work, we show that nanoporous gold can be exploited as plasmonic material for the mid-infrared region to obtain strong electromagnetic field confinement, co-localized with target molecules into the nanopores and resonant with their vibrational frequency. The effective optical response of the nanoporous metal enables the penetration of optical fields deep into the nanopores, where molecules can be loaded thus achieving a more efficient light-matter coupling if compared to bulk gold. In order to realize plasmonic resonators made of nanoporous gold, we develop a nanofabrication method based on polymeric templates for metal deposition and we obtain antenna arrays resonating at mid-infrared wavelengths selected by design. We then coat the antennas with a thin (3 nm) silica layer acting as target dielectric layer for optical energy transfer. We study the strength of the light-matter coupling at the vibrational absorption frequency of silica at 1250 cm-1 through the analysis of the experimental Fano lineshape that is benchmarked against identical structures made of bulk gold. The boost of optical energy transfer from free-space mid-infrared radiation to molecular vibrations in nanoporous 3D nanoantenna arrays can open new application routes for plasmon-enhanced physical-chemical reactions.