Thin metallic films on dielectric nanospheres are demonstrated to have a high potential for the fabrication of cost-effective SERS substrates. In addition to the morphological advantages that nanospheres offer for attaining a high density of hot spots, possessing shape adjustability by uncomplicated thermal treatment makes them an attractive platform for tuneable SERS substrates. Furthermore, when combined with the oblique angle metal deposition technique, adjustable gaps at a high density and adjustable shape of metal films, such as Ag films, can be achieved on nanospheres. Applying small changes in deposition angle can provide means for fine adjustment of the Raman enhancement factor (EF), resulting in EF up to 10⁸ measured using crystal violet dye molecule as a Raman analyte. This practice paves the way for the fabrication of high EF SERS substrates at a reasonable cost using a monolayer of self-organized nanosphere patterns. An ultra-thin Ag film coated at 5 tilt is shown to be an excellent substitute for a film deposited at 0 with double the thickness. There is a strong agreement between the experimental results and finite-elements-method-based Maxwell simulations exhibiting expected field enhancements up to 10⁹ at a tilt angle of 5.

电介质纳米球上的薄金属膜被证明在制造具有成本效益的 SERS 基板方面具有很高的潜力。除了纳米球为获得高密度热点提供的形态优势外，通过简单的热处理具有形状可调性，使它们成为可调谐 SERS 基板的有吸引力的平台。此外，当结合斜角金属沉积技术时，可以在纳米球上实现高密度的可调间隙和可调形状的金属薄膜，如银薄膜。应用沉积角度的微小变化可以提供微调拉曼增强因子 (EF) 的方法，导致 EF 高达 10 ⁸使用结晶紫染料分子作为拉曼分析物进行测量。这种做法为使用单层自组织纳米球图案以合理的成本制造高 EF SERS 基板铺平了道路。以 5 度倾斜涂覆的超薄 Ag 膜被证明是在 0 度下沉积且厚度加倍的薄膜的极好替代品。实验结果与基于有限元方法的 Maxwell 模拟之间存在很强的一致性，在倾斜角为 5 时，预期场增强高达 10 ⁹。