Improvement of efficiency of the single-layer polymer light-emitting diodes: the exciton confinement in the emitting layer by conjugated 1,3,4-oxadiazole

Two luminescent polymers, poly[(2-methoxy-(5-(2-(4-oxyphenyl)-5-phenyl-1,3,4-oxadiazole)-hexyloxy))-1,4-phenylenevinylene-alt-2,5-didodecyloxy-1,4-phenylenevinylene] (P1) and poly[(2-methoxy-(5-(2-(4-oxyphenyl)-5-(4-biphenyl)-1,3,4-oxadiazole)-hexyloxy))-