Observation of Molecules Adsorbed on III-V Semiconductor Quantum Dots by Surface-Enhanced Raman Scattering

Abstract

I report for the first time surface-enhanced Raman scattering (SERS) from molecules adsorbed on InAs/GaAs quantum dots. This result is very interesting because previous SERS experiments have been essentially restricted to molecules adsorbed on metallic surfaces. Raman scattering from pyridine molecules adsorbed on these III-V quantum dots structures is strongly enhanced relative to the same molecules in solution. The most interesting feature in the SERS spectrum is the appearance of a new vibrational band. I suggest that this line should be attributed to the chemisorbed pyridine that is formed by coordination of its lone pair electrons of the N atom to the semiconductor surface. This work provides unambiguous experimental evidence for SERS on III-V semiconductor quantum dots. Nanostructures are currently considered as potential building blocks for nanodevices. The performance and reliability of these devices strongly depend on the surface and interfacial properties of the constituent nanomaterials. Therefore, this work illustrates the considerable potential of SERS spectroscopy as a powerful new tool in nanoscience.