Electrically conducting poly(pyrazoles)
Inventors
Martin, Brett D. • Giles, Ian D. • Naciri, Jawad • Charles, Paul T. • Trammell, Scott A. • Deschamps, Jeffrey R. • DePriest, Jeffrey C.
Assignees
Publication Number
US-11028265-B2
Publication Date
2021-06-08
Expiration Date
2038-12-12
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Abstract
This disclosure concerns electrically conducting poly(pyrazoles). The concept of oligomerizing and polymerizing substituted aminopyrazole derivatives combined with a monomer activation procedure involving base-mediated conversion of the protonated pyrazole ring nitrogen to amine salt was developed. This disclosure concerns the specific chemistries needed for the synthesis of a pyrazole monomer used in the polymer synthesis. The procedure used for blending the novel polypyrazoles with other compounds needed for construction of solar cells for testing was developed. This disclosure concerns the concept of using these types of heteroatom-rich, electron-deficient oligomers or polymers as n-dopable or p-dopable electron acceptors in photovoltaic cells. This disclosure concerns synthesizing the starting monomer compounds and polypyrazoles.
Core Innovation
This disclosure concerns electrically conducting poly(pyrazoles) synthesized through the oligomerization and polymerization of substituted aminopyrazole derivatives. A monomer activation procedure involving base-mediated conversion of the protonated pyrazole ring nitrogen to an amine salt has been developed. The invention includes the specific chemistries necessary for synthesizing the pyrazole monomers used in polymer formation, as well as the procedures for blending these novel polypyrazoles with other compounds for constructing solar cells.
The invention addresses the concept of using heteroatom-rich, electron-deficient oligomers or polymers as n-dopable or p-dopable electron acceptors in photovoltaic cells. These materials exhibit high electron transport rates and versatile redox behavior, and can be synthesized in a simple one-step method using low-cost starting materials. This approach enables enhanced efficiency in polymer-based solar cells while significantly reducing synthesis costs compared to conventional polymer solar cell materials.
The background highlights the need to develop renewable energy sources such as solar power due to the finite nature of petroleum reserves. Silicon-based solar cells have high efficiency but are costly to manufacture, while polymer-based solar cells tend to be less expensive but often use costly polymers with low efficiency. The invention aims to overcome these limitations by providing inexpensive, easily synthesized polypyrazoles that improve solar cell efficiency at a lower cost.
Claims Coverage
The patent contains one independent claim concerning a method for producing an electrically conducting poly(pyrazole). Three main inventive features are articulated in the claim regarding the synthesis method.
Method for synthesizing poly(3-amino-4-nitropyrazole)
The method comprises adding water and potassium hydroxide to a flask, stirring to form a first solution, dissolving 4-nitro 3-aminopyrazole in the solution while heating, adding sodium or potassium persulfate, and forming electrically conducting poly(3-amino-4-nitropyrazole).
Formation of 1:1 molar complex at elevated temperature
Dissolving 4-nitro 3-aminopyrazole at 70° C. in the potassium hydroxide solution results in formation of a 1:1 molar complex between potassium and the deprotonated nitrogen of the pyrazole ring.
Controlled molar ratio of oxidant for polymerization
Adding sodium or potassium persulfate to the reaction solution in a final molar ratio of 1.2 moles persulfate to 1.0 moles of 4-nitro-3-aminopyrazole enables polymerization to form the conducting poly(pyrazole).
The independent claim covers a controlled synthesis method for poly(3-amino-4-nitropyrazole) involving solution preparation, complex formation at elevated temperature, and stoichiometric addition of a persulfate oxidant to produce the electrically conducting polymer.
Stated Advantages
Increases efficiency of photovoltaic cells compared to conventional polymers.
Significantly lower synthesis cost than virtually all commercially available solar cell polymers.
High electron transport rates and versatile redox behavior allow easy production and rapid investigation of derivatives.
Simple one-step synthesis using low-cost starting materials.
Solar cells constructed with the invented polymers produce photocurrents up to 5.1 times higher than similar cells with commercially available polymers, with responsivity up to 70-fold higher.
Documented Applications
Use of electrically conducting polypyrazoles as n-dopable or p-dopable electron acceptors in photovoltaic (solar) cells.
Construction of polymer-based solar cells incorporating polypyrazoles blended with other compounds for testing light-harvesting abilities.
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