Surface-enhanced Raman scattering from semiconductor nanostructures

Developing the surface-enhanced Raman scattering(SERS)substrate from noble metals to semiconductors would bring the SERS more promising applications in biomedicine detection.Based on the photo-induced charge transfer(PICT)mechanism the SERS model in the semiconductor-molecule system was built up.The analytical solution of the contribution from PICT to the molecular polarizability tensor was presented according to calculation of quantum mechanics,and the results suggested that arising SERS from the nanostructured Si substrate is possible.Experimental observation revealed that the numerous hydrogen atoms on the surface of the Hterminated Si nanowire(H-SiNW)arrays may serve as electron sink,and play a critical role in promoting efficient PICT and enable the SERS effect.The evident Raman enhancement of the standard probe Rodamine 6G(R6G),dye(Bu4N)2[Ru(dcbpyH)2-(NCS)2](N719),and the 4-aminothiophenol(PATP)from such substrates were detected.1 A significant enhancement of b2 modes could be observed from PATP chemisorbed on the H-SiNWs substrate,which indicated that a strong PICT process had taken place in the system.