Analysis of the absorption and emission spectra of poly(p-phenylene vinylene) films thermally converted at a relatively low temperature

In this work, we studied the absorption and emission spectra of spin-coated poly(p-phenylene vinylene) (PPV)–dodecylbenzenesulfonic counter-ion (DBS) films. The PPV–DBS films were obtained from a soluble precursor polymer thermally converted to PPV over a comparatively short time interval (30 min), and at low temperature (110 °C), conditions that yielded films with few structural defects. The line shape of the absorption spectra of the films deposited on glass substrates was analyzed by assuming a Gaussian distribution of segments along the main chain of PPV, and a conjugation degree between 3 and 15 units. For emission studies, only PPV segments with a high conjugation degree or a lower energy gap (HOMO–LUMO transition) contributed to the feature of the spectra.