Band gap control in conjugated oligomers and polymers via Lewis acids
View Patent ↗A method for altering the electronic and optical properties of a chemical compound having a band gap and a framework that includes π-delocalized electrons. The method includes complexing a Lewis acid to a basic site within the framework to form a Lewis acid adduct having a band gap that differs from the band gap of the chemical compound. The λ max of the Lewis acid adduct can be shifted to a longer wavelength in comparison to the λ max of the chemical compound. In various versions, the chemical compound can be a conjugated oligomer, a conjugated polymer, or a small molecule comprising a conjugated π-electron system. Electronic devices that include Lewis acid adducts are also provided.
1. An electronic device comprising a Lewis acid adduct, the adduct comprising a Lewis acid and a chemical compound comprising the following structure (I)
wherein the Lewis acid binds to structure (I).
2. The electronic device of claim 1 , further comprising a dithiophene, wherein structure (I) is arranged with the dithiophene according to the following structure (II)
wherein X is nothing or a thiophene ring and Y is ═CR 4 R 5 or ═SiR 4 R 5 ,
and wherein R 4 and R 5 are each independently a C 1-30 alkyl or C 5-30 aryl.
3. The electronic device of claim 1 , wherein the Lewis acid is BR 3 , AlR 3 , GaR 3 , R 2 BXBR 2 , R 2 AlXAlR 2 where R=F, Cl, Br, alkyl with C n (n=1 to 30), aryl with C n (n=5 to 30), perfluoroalkyl with C n (n=1 to 30), perfluoroaryl with C n (n=5 to 30), or any combination thereof, and X=alkyl with C n (n=1 to 30), aryl with C n (n=5 to 30), perfluoroalkyl with C n (n=1 to 30), perfluoroaryl with C n (n=5 to 30), or any combination thereof.
4. The electronic device of claim 1 , wherein the chemical compound is a conjugated oligomer, a conjugated polymer, or a small molecule comprising a conjugated π-electron system.
5. The electronic device of claim 4 , wherein the chemical compound is a chromophore.
6. The electronic device of claim 1 , wherein the chemical compound is one or any combination of the following:
wherein each R is independently a C 1-30 alkyl or C 5-30 aryl group, and each n is ≧1.
7. The electronic device of claim 6 , wherein the chemical compound is
and the Lewis acid is B(C 6 F 5 ) 3 .
8. The electronic device of claim 1 , wherein the device is an optoelectronic device, optoelectronic semiconductor chip, semiconductor thin-film, photovoltaic, semiconducting solar cell or dye-sensitized solar cell.
9. The electronic device of claim 1 , wherein the device is a solar cell.