Quantitative intramolecular fission in oligoacenes, materials, and methods of use thereof
The present invention provides soluble, stable singlet fission (SF) compounds, compositions, materials, methods of their use, and methods for their preparation that provide efficient intramolecular singlet fission (iSF) and multiple excitons. The SF compound may be a dimer, an oligomer, or a polymer of polyoligoacenes, where for example, the compound achieves a triplet yield reaching about 200% per absorbed photon. In this system, SF does not depend on intermolecular inter-actions. Instead, SF is an intrinsic property of the molecule and therefore occurs independent of intermolecular interactions. Singlet fission has the potential to significantly improve the photocurrent in single junction solar cells and thus raise the Shockley-Queisser power conversion efficiency limit from about 33% to about 46% or greater. Quantitative SF yield at room temperature has only been observed in crystalline solids or aggregates of higher acenes.
1. A soluble, stable singlet fission material, comprising an oligoacene of at least two covalently bound oligoacene monomers with or without a spacer, wherein the lower singlet exciton energy of one oligoacene monomer is essentially greater than about or essentially equal to about the sum of the energies of the triplet excitons of each of the at least two oligoacene monomers.
2. The material of claim 1 , wherein the at least two covalently bound oligoacene monomers are different.
3. The material of claim 1 , wherein the at least two covalently bound oligoacene monomers are the same.
4. The material of claim 1 , wherein the material comprises asymmetric oligoacene monomers.
5. The material of claim 1 , wherein the material is an oligomer of polyoligoacenes.
6. The material of claim 1 , wherein the material is a polymer of polyoligoacenes.
7. The material of claim 1 , wherein the material is essentially exoergic.
8. The material of claim 1 , wherein the material is essentially isoergic.
9. The material of claim 1 , wherein the material generates multiple excitons.
10. The material of claim 1 , wherein the material is selected from the group consisting of: pentacene-hexacene, 2,2′bipentacene, pentacene-tetracene, an oligomer of 1-10 tetracenes, a polymer of 11-200 tetracenes, an oligomer of 1-10 pentacenes, a polymer of 11-200 tetracenes, and a hetero polymer of pentacenes, tetracenes, and/or hexacenes of 1-200 monomers in length, and any combinations thereof.
11. An electronic, optical, or electrooptical component or device comprising a material of claim 1 .