Interactions between single-walled carbon nanotubes and tetraphenyl metalloporphyrins: Correlation between spectroscopic and FET measurements

The noncovalent functionalization, or complexation, of single-walled carbon nanotubes (SWNTs) with metallo-tetraphenyl porphyrins (M-TPPs) was monitored with UV-vis-NIR absorption spectroscopy and electroanalytical measurements using nanotube field-effect transistors (NTFETs). From combining both techniques, we have found that M-TTPs donate electron density exclusively into semiconducting SWNTs. Moreover, thin-film UV-vis-NIR absorption spectroscopy on SWNT/M-TPP complexes provides a well-resolved picture of the interaction between the SWNT S-1 band and the electron-donating M-TPP. In total, the electron-donating properties of four different M-TPPs containing Mn(III), Co(II), Cu(II), and Zn(II) were compared, and the electronic affects of each are discussed.