Aluminum (Al) is known as a plasmonic material effective in a wide frequency range up to the ultraviolet, while its plasmonic properties in the near infrared region have been less explored. In this study, up‐conversion (UC) photoluminescence is amplified by using an Al nanostructure to demonstrate that Al is a useful plasmonic material in the near infrared region as well. A periodic lattice of Al nanocylinders is selected as a plasmonic nanostructure, where the size of nanocylinder and the period of the lattice are tuned to match both the localized surface plasmon resonance and in‐plane diffraction to the absorption wavelength (λ = 980 nm) for the UC process. Core–shell‐type UC nanoparticles (NPs) are designed to suppress the energy transfer from NPs to Al cylinders which reduces the UC photoluminescence intensity. The resulting optimized core–shell UCNPs combined with the Al plasmonic lattice leads to over 100‐fold enhancement of UC intensity. The use of Al instead of conventional Au as a plasmonic material is beneficial from the point of view of low cost and abundance of element.

中文翻译：

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铝用于近红外等离子体：周期性晶格上核壳纳米粒子的放大上转换光致发光

已知铝（Al）是一种等离子体材料，可在高达紫外线的宽频率范围内发挥作用，而对近红外区域的等离子体性能却鲜有研究。在这项研究中，通过使用Al纳米结构来放大上转换（UC）光致发光，以证明Al在近红外区域也是有用的等离子体材料。选择Al纳米圆柱体的周期性晶格作为等离激元纳米结构，其中微调纳米圆柱体的尺寸和晶格的周期，以使局部表面等离振子共振和面内衍射与吸收波长（λ= 980 nm）相匹配UC流程。核壳型UC纳米颗粒（NPs）旨在抑制从NPs到Al圆柱体的能量转移，从而降低UC的光致发光强度。经过优化的核壳UCNP与Al等离子体晶格相结合，可使UC强度提高100倍以上。从低成本和大量元素的观点来看，使用Al代替常规的Au作为等离子体材料是有益的。