Triphenylamine- based π-conjugated dendrimers: convenient synthesis, easy solution processability, and good hole-transporting properties

Two, third-generation triphenylamine-based dendrimers (DT1 and DT2) were prepared through a simple convergent approach by using a combination of versatile carbon-carbon formation reactions. It is found that the pi-linkages connecting the periphery into the core have a pronounced effect on the properties of the material. The introduction of C C bonds in the periphery improves the photophysical behavior and optical qualities of the films in comparison with their introduction in the core of the dendrimer. Both dendrimers exhibit high T(g)s (above 240 degrees C) and high-lying HOMO energy levels of similar to 5.2 eV. As the holetransporting layer fabricated through a facile solution process, DT2 can endow an Alq(3) based multi-layer OLED device with a maximum brightness of 5020 cd m(-2), and a maximum current efficiency of 2.36 cd A(-1).