A series of Au films with different nominal deposition thickness d were fabricated on ionic liquid surfaces by thermal evaporation at room temperature, taken as surface-enhanced Raman scattering (SERS) substrates. Au atoms deposited on the liquid surfaces can diffuse and aggregate randomly and eventually form films with ramified structure, which consist of nanoparticles (NPs). There are amounts of ultrasmall (∼ 1 nm or smaller) nanogaps among the Au NPs, which can dramatically enhance Raman signal. Raman spectra of R6G were investigated with the assistance of the Au films. The results indicate that the Au films with higher thickness possess better SERS performance when 5.0 ≤ d ≤ 30.0 nm. A random distribution model of Au NPs was used in the finite-difference time-domain method and the simulation results are in good agreement with the experimental findings.

通过室温下的热蒸发在离子液体表面制备了一系列具有不同标称沉积厚度d的金膜，作为表面增强拉曼散射 (SERS) 衬底。沉积在液体表面的金原子可以随机扩散和聚集，最终形成由纳米粒子（NPs）组成的具有分枝结构的薄膜。Au NPs 中有大量的超小（~ 1 nm 或更小）纳米间隙，可以显着增强拉曼信号。在金膜的帮助下研究了 R6G 的拉曼光谱。结果表明，当 5.0 ≤ d时，具有较高厚度的 Au 薄膜具有更好的 SERS 性能。≤ 30.0 纳米。在有限差分时域方法中使用了Au NPs的随机分布模型，模拟结果与实验结果非常吻合。