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 π-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 °C) and high-lying HOMO energy levels of ∼5.2 eV. As the hole-transporting 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 .