X-ray Raman Scattering Study of Aligned Polyfluorene

We present a nonresonant inelastic X-ray scattering study at the carbon K edge on aligned poly[9,9-bis(2-ethylhexyl)-fluorene-2,7-diyl] and show that the X-ray Raman scattering technique can be used as a practical alternative to X-ray absorption measurements. We demonstrate that this novel method can be applied to studies on aligned π-conjugated polymers complementing diffraction and optical studies. Combining the experimental data and a very recently proposed theoretical scheme, we demonstrate a unique property of X-ray Raman scattering by performing the symmetry decomposition on the density of unoccupied electronic states into s- and p-type symmetry contributions.