Electronic properties of spiro compounds for organic electronics.

The electronic properties of p-type, n-type, and ambipolar spiro materials have been investigated using a combination of photoemission spectroscopy, electron energy-loss spectroscopy, and density functional based calculations. Our results provide insight into the occupied density of states as well as the electronic excitation spectra. Comparison of experimental and theoretical data allows the identification of the orbitals responsible for charge transport and optical properties.

Hole transparent and hole blocking transport in single-crystal-like organic heterojunction: when rods hold up disks.

Single-crystal-like organic heterojuntions are fabricated with disk-like molecules and different rodlike molecules. Hole transparent and blocking transport are demonstrated with photoemission spectroscopy and field-effect transistors. These results demonstrate a route to utilize adjustable interfacial electronic structure and control transport behavior in developing functional organic crystalline devices and crystalline nanocircuits.

Electronic excitations of potassium intercalated manganese phthalocyanine investigated by electron energy-loss spectroscopy.

The electronic excitations of manganese phthalocyanine (MnPc) films were studied as a function of potassium doping using electron energy-loss spectroscopy in transmission. Our data reveal doping induced changes in the excitation spectrum, and they provide evidence for the existence of three doped phases: K(1)MnPc, K(2)MnPc, and K(4)MnPc. Furthermore, the addition of electrons first leads to a filling of orbitals with strong Mn 3d character, a situation which also affects the magnetic moment of the molecule.

Spectroscopic characterization of N-doped single-walled carbon nanotube strands: an X-ray photoelectron spectroscopy and Raman study.

We have studied in detail the carbon and nitrogen bonding environments in nitrogen-doped single-walled carbon nanotubes (SWCNTs). The samples consisting of long strands of N-doped SWCNTs were synthesized using an aerosol assisted chemical vapor deposition method involving benzylamine-ethanol-ferrocene solutions. The studied samples were produced using different benzylamine concentrations in the solutions, and exhibited a maximum concentration of ca.