School of Physics and Electronics, State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan University, Changsha 410082, China.
Nanoscale. 2019 Jan 17;11(3):1245-1252. doi: 10.1039/c8nr09254k.
Reliable fabrication of gold nanoparticles with desirable size, geometry and spatial arrangement is essential for plasmonic applications. A common fabrication flow usually involves electron-beam lithography and a vacuum-evaporation-based lift-off process or etching. In this work, we evaluate an alternative approach to directly fabricate a plasmonic gold nanoparticle array without involving the vacuum evaporation process by using a chloroauric acid/poly(vinyl pyrrolidone) (HAuCl4/PVP) hybrid as a functional electron-beam resist. Systematic experiments were conducted to investigate the patterning behaviors in the fabrication process. With the optimized fabrication parameters, we show that the HAuCl4/PVP composite resist has a high patterning resolution and pure gold nanoparticles with tens of nanometers can be obtained after an annealing-based pyrolysis process. More particularly, compared to the patterned plasmonic gold nanoparticles obtained by conventional methods, the gold nanoparticles fabricated by our method can be transferred to soft substrates due to the absence of an adhesion layer, enabling various potential applications in flexible and stretchable optics. As an example, we demonstrated that the transferred gold nanoparticle array can be conformably assembled onto a flat gold surface to form a particle-on-film structure for surface-enhanced Raman scattering (SERS) applications.
可靠地制备具有所需尺寸、形状和空间排列的金纳米粒子对于等离子体应用至关重要。一种常见的制造流程通常涉及电子束光刻和基于真空蒸发的剥离工艺或刻蚀。在这项工作中，我们评估了一种替代方法，即通过使用氯金酸/聚（N-乙烯基吡咯烷酮）（HAuCl4/PVP）杂化作为功能电子束抗蚀剂，直接制造等离子体金纳米粒子阵列，而无需涉及真空蒸发过程。系统地进行了实验以研究制造过程中的图案化行为。通过优化制造参数，我们表明 HAuCl4/PVP 复合抗蚀剂具有高的图案化分辨率，并且在退火基热解过程之后可以获得具有数十纳米的纯金纳米粒子。更特别地，与通过常规方法获得的图案化等离子体金纳米粒子相比，由于不存在粘附层，我们通过该方法制造的金纳米粒子可以转移到软基底上，从而为柔性和可拉伸光学领域的各种潜在应用铺平了道路。作为一个例子，我们证明了转移的金纳米粒子阵列可以贴合地组装到平坦的金表面上，以形成用于表面增强拉曼散射（SERS）应用的粒子在薄膜上的结构。
