“…Instead, either triplet-triplet annihilation (TTA), by which the electronic ground state is recovered, takes over, or up-conversion via geminate triplet-triplet recombination (G-TTA-UC) occurs to yield (S 1 S 0 ). 33,34,[35][36][37][38][39][40][41][42]43 Recently, several families of molecular building blocks have been demonstrated to be SF-active: these include first and foremost linear acenes 12,[44][45][46][47][48][49][50][51][52] such as tetracene and pentacene, followed by carotenoids, [53][54][55][56][57][58][59] diketopyrrolopyrroles, 26,32,[60][61][62][63][64][65][66][67] and rylenes 31,[68][69][70][71][72][73][74][75][76] such as perylene-and terrylene-diimides. Lat...…”