A new triphenylamine-based hyperbranched polyfluorene with oxadiazole units on its side chains

A new triphenylamine-based hyperbranched polymer with electron deficient units of oxadiazole on its side chains was successfully prepared by a modified Suzuki polycondensation with Pd(PPh3)4 as a catalyst, K2CO3 as a base, and a mixture of THF/toluene (1:1) as the solvent. The electron deficient units of oxadiazole were used to improve the electron injection and transport of the polymer. The results of the cyclic voltammetry (CV) of the polymer indicate that the HOMO and LUMO energy levels match well with the work function of the ITO/PEDOT anode and the metal cathode, respectively. Moreover, the hyperbranched polymer shows blue-emission and the hyperbranched structure effectively suppressed the formation of the aggregates/excimers in the polymer film.