c Obtained from the integrated prompt and delayed emission of the TRPL decays. those of the five derivatives. As previously mentioned, Tenopala et al. found that generally for emitters with MW> 600 g/mol, the anisotropy factor improves with higher MW, higher xE/xH (ratio of the length of the emitter to the host), and lower zE (thickness of the emitter) (Table ). All five derivatives (as well as the parent compound DMAC-TRZ) have the same zE value, thus it will not be considered in this analysis. The orthogonal conformation of the material means that the donor is responsible for the width of the material (yE) and the thickness of the material is dependent on the triazine, which is the same in all materials. The material with the lowest a value is dPh-DMAC-TRZ, ). This verifies that at higher current densities, the device roll-off is proportional to the triplet harvesting efficiency (kRISC) of each individual emitter To investigate the same luminance trend, we used lifetime extrapolation from the accelerated tests of DMAC-TRZ at different current densities (Figure ). From this plot we can extract the estimated lifetime of DMAC-TRZ devices at different luminance, and the cross comparison with the other derivatives at the same luminance is shown in Table . The estimated lifetime of DMAC-TRZ is higher compared to all the other derivatives at the same luminance (but different current density) presumably because of its higher internal quantum efficiency and slightly different γ factor.