Solution-processable, crystalline material for quantitative singlet fission

Amorphous nanoparticles of the singlet fission chromophore 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-Pn) are fully crystallized through co-precipitation with a chemical additive. Time-resolved measurements indicate that singlet fission in the crystalline nanoparticles is quantitative, or lossless, whereas losses are evident in the amorphous nanoparticles as a result of frustrated triplet pair separation. Because triplet pairs formrapidly and separate slowly in amorphous material, mixed-phase samples are unable to compensate for these losses.