Plasmonic effect of bimetallic TiO2/Al2O3 nanoparticles in tellurite glass for surface-enhanced Raman scattering applications

Understanding the surface plasmon resonance (SPR) assisted spectroscopic properties of the glasses via the incorporation of the bimetallic nanoparticles (NPs) is a prerequisite for the surface-enhanced Raman scattering (SERS) applications. The texture, structures, and optical traits of melt-quenched synthesized Er3+-doped tellurite glasses were modified by incorporating bimetallic TiO2/Al2O3 NPs. The as-quenched samples were characterized using diverse techniques, where the X-ray diffraction (XRD) analyses confirmed their amorphous nature. The surface roughness of the glass was improved from 6.1 nm (TZNETi glass) to 9.3 nm (TZNETiAl0.6 glass). The SPR bands of the bimetallic TiO2/Al2O3 NPs were probed at 554 nm and 827 nm. The photoluminescence (PL) in-tensity enhancement was evidenced due to the NPs SPR-mediated strong local field effect and energy transfer between the metallic NPs and Er3+ ions. The amplification in the Raman intensity due to the NPs SPR-mediated enhanced electromagnetic field contribution. The proposed glass system may be beneficial as substrate for the SERS applications.