Synthesis of dimesitylborane-substituted phenylcarbazoles as bipolar host materials and the variation of the green PHOLED performance with the substituent position of the boron atom.

Two structural isomers of the bipolar host material containing the dimesitylborane moiety were synthesized and their device performance was investigated. The quantum efficiency of the devices depends on the substituent position of the dimesitylborane moiety. The maximum external quantum efficiency of the device reached as high as 23.8% with a green color coordinate of (0.30, 0.63).