Synthesis of p-type conjugated dendrimers bearing phenothiazine moiety at the periphery and their light-emitting device characterization

New dendrimers bearing a phenothiazine heterocyclic building block have been successfully prepared and their absorption and emission properties have been investigated in terms of photoluminescence (PL) and electroluminescence (EL). Particularly, the EL has been studied precisely in the heterostructural devices that are fabricated with two dendrimers. The spectrum and the intensity of EL and PL are varied with the number of generation. Significant difference of the I–V–L characteristics and the external quantum efficiency in the dendrimer devices reveals that the EL performance of the higher-generation dendrimers is higher than that of the lower-generation ones. These results suggest that the site isolation between the chromophores suppresses the non-radiative decay process and reduces the interchain molecular excimer emission from the aggregated dendrimers.