The combination of broadened PL spectra and lower FPL in the neat films compared to the doped films suggests that there is some aggregation-caused quenching (ACQ) of the emission in the neat films (Figures 8g, h Figure ). The higher ΦPL and reduced spectral broadening of mer-Ir(tfpi_Bn)3 in the neat film compared to fac-Ir(tfpi_Bn)3 suggest the meridional isomer is less susceptible to ACQ, which makes sense as one side of a facial isomer is relatively open and therefore able to aggregate at high concentration. The higher FPL of mer-Ir(tfpi_tmBn)3 versus mer-Ir(tfpi_Bn)3 and the less pronounced reduction of the FPL in the neat film reflects a greater effectiveness for the bulkier trimethylbenzyl group to inhibit intermolecular interactions and aggregation that contribute to the quenching of the emission.