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

We present the steady-state and time-resolved photoluminescence (PL) spectr a of poly(p-phenylenevinylene)derivatives, which exhibit a marked dependenc e on the side chains attached to the main chain. The PL spectra of poly(2-c arbazolyl-p-phenylenevinylene) (pCzPV) and poly[2-[9-(10-phenyl)anthryl]-1, 4-phenylenevinylene] (PPAPV) exhibit a vibronic structure with relatively s hort PL lifetimes. On the other hand, poly[[[2-[9-(10-phenyl)anthryl]phenox y]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-te rt-butylphenyl)-1,3,4-oxadiazole]-p-enylenevinylene] also exhibits the long PL decay time as well as the structureless and redshifted emission. The di fference in the photophysical properties of these polymers is discussed in terms of the electronic nature of the excited states influenced by the pend ent groups.