, after which the TADF-photocatalyst behaves as if it were a fluorophore comprising only a singlet excited state, and the plot becomes linear. Literature reports of fluorescence quenching experiments using TADF fluorophores indeed often depict linear Stern-Volmer plots, which can occur when the first datapoint is taken at a concentration at which full triplet quenching already occurs. However, in such cases, the y-intersect (i.e., [Q] = 0) is at a value greater than 1 (see Figure ), which is an easily overlooked indication that equation 6 does not apply. Instead, in the hypothetical limit where