Time-resolved photoluminescence study of poly(p-phenylenevinylene) derivative polymers

We present the steady-state and time-resolved photoluminescence (PL) spectra of poly(p-phenylenevinylene)derivatives, which exhibit a marked dependence on the side chains attached to the main chain. The PL spectra of poly(2-carbazolyl-p-phenylenevinylene) (PCzPV) and poly[2-[9-(10-phenyl)anthryl]-1,4-phenylenevinylene] (PPAPV) exhibit a vibronic structure with relatively short PL lifetimes. On the other hand, poly[[[2-[9-(10-phenyl)anthryl]phenoxy]hexoxy]-1,4-phenylenevinylene] (PAHPV) shows the broad and structureless emission with a long tail. In addition, the PL decay time of PAHPV is about 3 times longer than that of PCzPV or PPAPV. Poly[[2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole]-p-enyleneviny lene] also exhibits the long PL decay time as well as the structureless and red-shifted emission. The difference in the photophysical properties of these polymers is discussed in terms of the electronic nature of the excited states influenced by the pendent groups.