A span-new electron-deficient moiety 2,5-diazarcarbazole (25NCz) with high T1 = 2.77 eV was firstly designed and synthesized, which had enormous potential to construct organic electronic materials in photoelectric field. Herein, 25NCz as large rigid-type periphery functionalized group, was introduced to develop novel electron transporting materials (ETMs) by grafting large rigid-type π-conjugated core anthracene. Two novel ETMs p-S25NCzDPA and p-D25NCzDPA were designed and developed. Due to the dual characteristics of rigidity and electron-accepting of the 25NCz, as expected, these two ETMs possessed good thermal stability and high electron mobility. When triplet-triplet fusion (TTF) sky-blue fluorescent OLEDs based on these two novel ETMs were manufactured, they exhibited superior performances. In particular, the maximum external quantum efficiency (EQE) reached 7.45% and the EQE kept 7.45% at the luminance of 50,000 cd m−2 for p-S25NCzDPA based device. This work rationally demonstrated that the significance of newly developed electron-deficient moiety 25NCz in designing ETMs for high-performance OLEDs.