A hybridization-induced charge-transfer state energy arrangement reduces nonradiative energy loss in organic solar cells

Here, we explain why the Energy Gap Law and the energy inversion related to the charge-transfer state have opposite effects on the trend of nonradiative energy loss of organic solar cells. The root is the existing condition of energy inversion. There is indeed a certain probability of energy inversion, but it will eventually be implicit or explicit as determined by the hybridization, which depends on the electron-withdrawing unit of the donor, giving rise to different stacking sites. The triplet-state hybridization leads to an explicit characteristic, while singlet-state hybridization leads to an implicit characteristic. This work demonstrates the non-synergistic effect of charge transfer state and energy inversion on regulating nonradiative loss and blending morphology.