Singlet fission in organic thin films of 1,3-diphenylisobenzofuran and cibalackrot (presentation video)

Efficient singlet fission has been reported in polycrystalline thin films of 1,3-diphenylisobenzofuran. Two conformational polymorphs have been characterized by various spectroscopic techniques. Thin films exhibit 200% triplet quantum yield at 77 K, as determined by ultrafast transient absorption measurements. Rapid excimer formation presents a significant energetic barrier to triplet formation.