Highly efficient blue emitters based on the Lewis acid-base carbazole-pi-dimesitylborane framework are synthesized and characterized. Among four bipolar blue fluorophores, the nondoped OLED fabricated with CzThB exhibits the best performance blue electroluminescence with CIEx, y (0.13,0.21), maximum electroluminance of 28 300 cd m(-2) and external quantum efficiency of 6.9%.