Author/Authors :
Comoretto، نويسنده , , D. and Dellepiane، نويسنده , , Alastair G. W. Moses، نويسنده , , D. and Cornil، نويسنده , , J. and dos Santos، نويسنده , , D.A. and Brédas، نويسنده , , J.L.، نويسنده ,
Abstract :
We report polarized, near-normal incidence, absolute reflectivity spectra of highly stretch-oriented unsubstituted poly(p-phenylene-vinylene). The data show a well-resolved vibronic progression in the lowest optical transition, a high dichroic ratio and weak signals due to conjugated segments with reduced effective conjugation length. On the high-energy side of the spectra, other transitions mainly related to excited states involving localized levels are detected. The low-temperature spectra confirm these assignments. The polarization properties of the reflectivity spectra are discussed in relation to correlated quantum–chemical calculations.
