Enhanced Raman Scattering of Ultramarine on Au-coated Ge/Si-nanostructures

Abstract

Semiconductor self-assembled Ge-on-Si quantum dot structures coated with Au film were successfully employed as surface-enhanced Raman scattering (SERS) substrates to characterize ultramarine blue inorganic art pigment. To assign the bands and to reveal the enhancement mechanisms, the quantum-chemical calculations of vibration spectra of linear and cyclic model compound of SiO 4 and AlO 4 tetrahedra were carried out. The overtones are observed in the SERS spectra and the unharmonicity constants were estimated. The development of a series of new bands in SERS spectra of ultramarine are discussed in terms of electro-optical unharmonicity.

Observation of High-Order Overtones and Combinations in Surface-Enhanced Raman Scattering: The Essential Role in Elucidation of the Chemical Mechanism

“…The demand for contemporary SERS measurements in the range of higher wavenumbers is conditioned by the limit of recent observations of overtones for the second order. , The overtones of higher orders have been recorded only for inorganic species consisting of heavy elements. − For these compounds, they are affected by localized surface plasmon resonance due to small Raman shifts and cannot be considered as true signs of the chemical contribution. A coordinated theoretical and experimental study of intensive high-order modes may be helpful to validate the necessity of including the higher-order Albrecht terms and can give an insight into the anharmonicity and the excited-state dynamics.…”

Enhancement of Raman scattering of light by ultramarine microcrystals in presence of silver nanoparticles

“…The ν 1 ‐band shift from 543 to 541 cm –1 is within the accuracy of measurements. The enhancement and development of pronounced complex modes has been recently interpreted as manifestation of electro‐optical vibrational unharmonicity promoted in the presence of SERS‐active material/substrate …”

“…Therefore, the extension of traditional SERS techniques to microcrystalline inorganic materials including art pigments has yet to be performed. Recently, we have reported on pronounced Raman scattering enhancement of ultramarine microcrystallite pigment using metal‐coated Ge‐on‐Si templates as substrates …”

Gold organosols for multicomponent surface‐enhanced Raman spectroscopy analysis of paintings

“…Nowadays, there are some smart nondestructive techniques for organic pigments identification in textile, tapestry, prints, and on the wood panels . Recently, we demonstrated the possibility to enhance Raman signal of inorganic microcrystals …”