Zhao Zhi-Jun, Ahn Junseong, Ko Jiwoo, Jeong Yongrok, Bok Moonjeong, Hwang Soon Hyoung, Kang Hyeok-Joong, Jeon Sohee, Choi Jungrak, Park Inkyu, Jeong Jun-Ho
Nano-Convergence Mechanical Systems Research Division, Korea Institute of Machinery and Materials, 156, Gajeongbuk-ro, Yuseong-gu, Daejeon 34103, South Korea.
Department of Mechanical Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 34141, South Korea.
ACS Appl Mater Interfaces. 2021 Jan 20;13(2):3358-3368. doi: 10.1021/acsami.0c18122. Epub 2020 Dec 21.
A novel method for fabricating shape-controlled and well-arrayed heterogeneous nanostructures by altering the melting point of the metal thin film at the nanoscale is proposed. Silver nanofilms (AgNFs) are transformed into silver nanoislands (AgNIs), silver nanoparticles (AgNPs), and silver nanogaps (AgNGs) that are well-ordered and repositioned inside the gold nanoholes (AuNHs) depending on the diameter of the AuNHs, the thickness of the AgNF, and the heating temperature (120-200 °C). This method demonstrates the ability to fabricate uniform, stable, and unique structures with a fast, simple, and mass-producible process. For demonstrating the diverse applicability of the developed structures, high-density AgNGs inside the AuNHs are utilized as surface-enhanced Raman spectroscopy (SERS) substrates. These AgNGs-based SERS substrates exhibit a performance enhancement, which is 1.06 × 10 times greater than that of a metal film, with a relative standard deviation of 19.8%. The developed AgNP/AgNI structures are also used as nonreproducible anti-counterfeiting signs, and the anti-counterfeiting/readout system is demonstrated via image processing. Therefore, our method could play a vital role in the nanofabrication of high-demand nanostructures.
提出了一种通过在纳米尺度上改变金属薄膜的熔点来制备形状可控且排列良好的异质纳米结构的新方法。银纳米薄膜（AgNFs）被转变为银纳米岛（AgNIs）、银纳米颗粒（AgNPs）和银纳米间隙（AgNGs），它们根据金纳米孔（AuNHs）的直径、AgNF的厚度以及加热温度（120 - 200°C）在金纳米孔内有序排列并重新定位。该方法展示了通过快速、简单且可大规模生产的工艺制造均匀、稳定且独特结构的能力。为了证明所开发结构的多种适用性，将AuNHs内的高密度AgNGs用作表面增强拉曼光谱（SERS）基底。这些基于AgNGs的SERS基底表现出性能增强，比金属薄膜高出1.06×10倍，相对标准偏差为19.8%。所开发的AgNP/AgNI结构还用作不可复制的防伪标识，并通过图像处理展示了防伪/读出系统。因此，我们的方法在高需求纳米结构的纳米制造中可能发挥至关重要的作用。
