Notably, their emission spectra in mCP are red-shifted compared to those in dilute toluene, which given the low polarity of this host, implies the presence of host/guest interactions and likely contribution from aggregates in the solid state even at the low doping concentration employed. Benefiting from the delicate balance between CT and SRCT, 3TPA-DiKTa shows a higher FPL of 93% than 3DPA-DiKTa (FPL = 60%) in 2 wt% mCP evaporated film.