Technologies Available for License

2014-008: Organic oligomers and polymers for efficient intramolecular singlet fission

Invention: 2014-008

Patent Status: U.S. Patent Number 10,636,974 was issued on April 28, 2020

For technical and licensing related questions, email tcp@bnl.gov.

Summary

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A design strategy for intramolecular singlet fission mediated by charge-transfer states in donor–acceptor organic materials.

This joint invention between BNL and Columbia University provides generalized molecular compositions for the development of tunable materials for high efficiency (> 33.7%) Photovoltaic (PV) devices based on multiple exciton-generation processes. The inventive materials include novel organic oligomers and polymers designed to exhibit strong intrachain donor-acceptor interactions and deliver intramolecular singlet fission, where triplet populations can be generated in very high yields of, e.g., 170% or more. The fundamental attributes of this invention can lead to the development of new fission-capable materials with tunable electronic structure, as well as a deeper fundamental understanding of Multiple Exciton Generation (MEG) to improve the performance of Organic Photovoltaics (OPVs).

Description

Our invention demonstrates that strong intrachain donor-acceptor interactions are a key design feature for organic materials capable of intramolecular singlet fission. By conjugating strong-acceptor and strong-donor building blocks, small molecules, and polymers with charge-transfer states that mediate population transfer between singlet excitons and triplet excitons are synthesized. Polymers of the invention include those of the general formulas: [SD-SA]n, [WD-SA-D-SA-WD]n, [SA-D-SA-WD]n, [SD-SP-SA]n, [SD-SP-SA-SP]n, and the like, wherein D represents an electron donor; SA represents a strong electron acceptor (e,g., thiophene oxide); SD represents a strong electron donor (e,g., benzodithiophene); WD represents a weak electron donor (e,g., substituted thiophene); SP represents a spacer (e,g., conjugated aromatic compounds); and n represents a positive integer. Using transient optical techniques intramolecular singlet-fission yields up to 170% was observed in this new family of materials which allows for establishing a new design framework for fission-capable materials.

Journal Publication & Intellectual Property

• A design strategy for intramolecular singlet fission mediated by charge-transfer states in donor acceptor organic materials (.pdf)
• New insights into the design of conjugated polymers for intramolecular singlet fission (.pdf)
• US 10,636,974 (.pdf)