FPL decreased along with a red-shifted emission (Figure and Table ) upon an increase of the doping concentration of each emitter in mCP host. The red-shifted emission can be ascribed in part to aggregate formation. As shown in Figure , 3TPA-DiKTa emits at lPL = 551 nm with FWHM of 58 nm (245 meV) in 2 wt% mCP evaporated film, whereas 3DPA-DiKTa shows a more red-shifted emission at lPL = 617 nm with FWHM of 56 nm (198 meV).