-0.07 eV, 1 wt% in Zeonex) with 34CT (DEST: 0.29 eV, 1 wt% in Zeonex) and 35CT (DEST: There are also a number of analogue emitters possessing three carbazole donors. Compared with 35CT (∆EST: 0.23 eV; FPL: 43% in toluene), TCzTRZ (∆EST: 0.16 eV; FPL: 100% in toluene), as shown in Figure , possesses a smaller DEST coupled with a significantly improved FPL. The structural difference between these two compounds is the addition of a third carbazole para to the triazine, which results in a HOMO that is distributed over the three donor carbazoles.