The FPL of TRZoCz and TRZotCz are 96% and 98%, respectively, for the 10 wt% films in DPEPO. The PL spectra are red-shifted compared to that of Cz-TRZ due to the increased conjugation within their structures, the photophysics of the two compounds are also less sensitive to the doping concentration. The EQEmax of the TRZotCz ~480/-/-(PhMe) -/98/25 (10% in DPEPO ) 0.06 -5.9.