Perhaps the most notable observation from Fig. is that the effective rate constants for all three values of λ D become nearly identical for larger positive detunings. This is in stark contrast to the negative detunings where the non-zero λ D rate constants are orders of magnitude smaller than the λ D = 0 rate constant. The reasons for this effect at large detunings are similar to the reasons why the effective rate constants for the √ Ng c = 300 meV case in Fig. are nearly the same for all three λ D values. The large positive detunings increase the spectral gap between the UP and the dark states which significantly decreases the transfer rate from the UP to the dark states. In addition, the decrease of UP matter character at positive detunings also decreases the transfer rate from the UP to the dark states since that rate is proportional to the UP matter character. This significantly decreased transfer rate from the UP to the dark states at large positive detunings becomes negligible compared to the increased rate from the UP to the acceptor states which essentially eliminates the effect of the dark states on the PMET process for large positive detunings. As such, our theoretical work recommends that future experimental work uses positive detunings to (1) enhance the effective driving force of PMET, and at the same time, (2) decrease the transition rate from UP to the dark states.