Energy transfer in a multilayer film via spin self-assembly

We have fabricated ultrathin multilayer films via spin self-assembly quickly and easily, using cationic poly(p-phenylene vinylene) (PPV) precursor, and as its counterparts, anionic poly(styrene-4-sulfonate) (SPS) and dodecylbenzenesulfonate (DBS). The PPV precursor incorporated with DBS could be thermally converted to PPV rapidly at a relatively lower conversion temperature than the self-assembled (PPV precursor/SPS) film. When we thermally converted an alternating multilayer film of [(PPV precursor/SPS)5/(PPV precursor/DBS)5], at a low temperature (110 °C), more converted PPV with longer conjugation length (PPV/DBS) and less converted PPV with shorter conjugation length (PPV/SPS) coexisted. As a result, the multilayer film with the different energy band-gaps could be fabricated by thermal-converting an alternating multilayer film at a low conversion temperature in a relatively short time. UV/VIS absorption spectra and photoluminescent spectra demonstrated not only the structural regularity and reproducibility of this system but also the energy transfer between the layers with different conjugation lengths.