Thus, novel functional materials with desired chemical and physical properties should be developed to combine with ingeniously designed device architectures. In particular, blue fluorophor is one of the indispensable and important parts in hybrid WOLEDs; its characteristics such as quantum yield and energy levels help guide us toward strategic device engineering, which strongly affects the device performance. Although some blue fluorophors with high triplet state were synthesized and successfully applied in hybrid WOLEDs, novel ones should be available to further boost the efficiency.