Enhancement of Raman Scattering by Ultramarine Using Silver Films on Surface of Germanium Quantum Dots on Silicon

摘要

The germanium on silicon (Ge-on-Si) semiconductor nanostructures with a vacuum-deposited silver coating are tested as substrates for detecting microamounts of inorganic crystalline ultramarine pigment by enhanced Raman scattering (SERS). At least tenfold enhancement of Raman lines is obtained. The quantum-chemical calculations are performed and used to assign the bands in the Raman spectra. A significant electrooptic anharmonicity of vibrations of chromophore groups in the presence of an SERS-active compound is found.