As explained earlier, our goal of minimising efficiency roll-off requires us to minimise the triplet population relative to the singlet population. Here, we can see that this can be achieved by maximizing 𝐾 eq . Furthermore, according to Le Chatelier's principle, an equilibrium can be moved to a desired product by removing the product out of the equilibrium. In the case of a TADF OLED, the radiative decay of S 1 excitons is desired.