The invention relates to the use of a multinuclear metal or transition metal complex in an organic electronic device, said complex having a small ΔE spacing, particularly between 50 cm−1 and 2000 cm−1, between the lowest triplet state and the singlet state that is higher and is achieved by thermal backfilling from the triplet. The invention further relates to the use of the strong absorptions of such multinuclear metal complexes, particularly in OSCs.