The synthetic procedures of the deuterated exciplex were illustrated in supplementary information. Both two compounds synthesized through a series of nucleophilic substitution and Buchwald-Hartwig coupling reaction. The final products were further purified using temperature-gradient vacuum sublimation, of which the chemical structures were then fully characterized by 1 H NMR, C NMR and MALDI-TOF mass spectrometry. The detailed synthetic procedures, device fabrication and characterization data are provided in the supplementary information.