Interchain charge-transfer states in poly[(2,5-diphenylene-1,3,4-oxadiazole)-4,4′-vinylene] (O-PPV) oligomer

We synthesized the soluble poly[(2,5-diphenylene-1,3,4-oxadiazole)-4,4′-vinylene] (O-PPV) oligomer. The photoluminescence (PL) properties are investigated using absorption and selective excitation measurements for different O-PPV concentrations in solid-state O-PPV/PEO blends, as well as comparing PL spectra in dilute solution and solid state pristine O-PPV. The results show that solid-state O-PPV emission arises from interchain charge-transfer states due to interchain effects. In the O-PPV/PEO blends PL spectra, we find that the PL spectra excited at 300 nm are different from those at 350 nm. We think that this is directly associated with the properties of intrachain excited states in conjugated polymers.