In organic solar cell (OSC) development, materials with minimal energy offsets between the lowestenergy locally excited (LE) and intermolecular CT singlet states (ΔELE-CT = ELE1 -ECT1, Fig. ) can reduce nonradiative voltage loss while maintaining high power conversion efficiency 23 -29 . This leads to enhanced open-circuit voltages, notwithstanding the limited driving force for Frenkel exciton dissociation inherent in a small ΔELE-CT . On this basis, non-fullerene acceptors for OSCs have been designed to have high absorption and emission properties and utilized for organic light-emitting diodes (OLEDs) with near-infrared luminescence . Energy offsets may be minimized by selecting materials that either have small differences in their lowest unoccupied molecular orbital (LUMO) energies (ΔELUMO = ELUMO,D -ELUMO,A) or their highest occupied molecular orbital (HOMO) energies (ΔEHOMO = EHOMO,D -EHOMO,A), depending on whether the electron donor or acceptor component has the smallest optical gap in the blend, as show in Eq. ( ).