A comparative study of SERS from α-sexithiophene and other thiophene oligomers

✍ Scribed by Uttam K. Sarkar; Subhasis Chakrabarti; T.N. Misra; A.J. Pal

• Book ID: 103033712
• Publisher: Elsevier Science
• Year: 1992
• Tongue: English
• Weight: 389 KB
• Volume: 200
• Category: Article
• ISSN: 0009-2614
• DOI: 10.1016/0009-2614(92)87044-p

✦ Synopsis

Surface enhanced Raman scattering (SERS) is observed from a-sexithiophene (6T) adsorbed on Ag sols and compared with other oligothiophenes. Concentration dependence and Raman excitation frequency dependence of the enhancement factor have been studied and explained in terms of "classical" and "chemical" contributions. Experimental results suggest that smaller oligomers form a monomolecular layer on the silver surface at a lower concentration than the longer oligomers. Also, the decrease in twist angle between the thiophene rings in the surface adsorbed state is larger for the smaller oligomers. Possible orientations of different oligothiophenes, on the silver surface, have been discussed.