Functionalization of carbon nanotubes
Since "synthesis of" new properties is our main mandate, time-to-time we also turn our attention to inorganic materials. When the size of the later is reduced to that of several nanometer, they often start behaving as classical molecules, showing sharp electronic levels (quantum confinement) and becoming soluble (and thus processable) in organic solvents.
In the past, we have demonstrated that single-wall carbon nanotubes, when cut in short "cylinders" can be asymmetrically functionalized (electron-donating substituents on one side and electron-accepting substituents on the other). We showed that when immobilized in monolayers, such asymmetrically-functionalized nanotubes rectify electrical current, mimicking the behavior of classical p-n junction diode at the nanoscale.
More recently, we have demonstrated that "up-converting" lanthanide-based nanoparticles (Yb/Er-doped NaYF4) can be coupled with CdSe quantum dots in a new type of heterostructure that displays pronounced photoconductivity when excited by NIR light (ie, below its semiconducting band-gap).
NIR Photoresponse in New Up-Converting CdSe/NaYF4:Yb,Er Nano-Heterostructures,
C. Yan, A. Dadvand, F. Rosei*, D.F. Perepichka*, J. Am. Chem. Soc. 2010, 132, 8868.
Multiple NaNbO3/Nb2O5 Nanotubes: A New Class of Ferromagnetic/Semiconductor Heterostructures,
C. Yan, L. Nilikova, A. Dadvand, C. Harnagea, A. Sarkissian, D.F. Perepichka,* D. Xue,* F. Rosei*, Adv. Mater. 2010, 22, 1741-1744.
Metal Nanoparticles: From ″ Artificial Atoms ″ to ″ Artificial Molecules ″ ,
D.F. Perepichka, F. Rosei, Angew. Chem. Int. Ed. 2007, 46, 6006-6008.
Rectifying diodes from a symmetrically functionalized single wall carbon nanotubes,
Z.Wei, M.Kondratenko, D.F.Perepichka, L.H.Dao, J. Am. Chem. Soc. 2006, 128, 3134-3135.PDF
D.F.Perepichka, F.Rosei, Small 2006, 2, 22.
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