Silver loaded anodic aluminum oxide defective photonic crystals and their application for surface enhanced Raman scattering

Abstract

Here, the fabrication of the Ag nanoparticles loaded one-dimensional anodic aluminum oxide defective photonic crystals (Ag@AAO DPCs) with controllable structure parameters is reported using specially designed periodic pulse anodization and vacuum thermal evaporation techniques. The constructed Ag@AAO DPCs films have ordered distributed nanopore surface, high-quality defect state and tunable photonic band gap, which are ideally suited for the surface-enhanced Raman scatting (SERS) substrates that use local electric field and defect state resonance mechanisms. These sbustrates exhibit excellent SERS performance for rhodamine B (rhB) testing with high sensitivity and reproducibility. In which the logarithmic intensity of Raman signal peak at 1646 cm−1 versus the concentration of rhB presents a linear relationship, and the detection limitation can reach to the order of 10−10 mol/L, the enhancement factor can increase to the order of 105, especially when the defect state energy level position is matched with the incident light. This means that the Ag@AAO DPCs can be used as SERS substrates for the trace detection of organic dye molecules. Compared to the common Ag@AAO substrate, the main reasons for the SERS signal enhancement of the Ag@AAO DPCs are attributed to the synergistic effect of the enhanced local electric field strengthened by the Bragg reflection of PC structure and electron transformation induced by the defect state resonance with the incident light. This would be a promising way for applications for surface enhanced Raman scattering.