Organic photovoltaic cells and non-fullerene acceptors thereof
View Patent ↗Organic photovoltaic cells (OPVs) and their compositions are described herein. In one or more embodiments, the acceptor with an active layer of an OPV includes is a non-fullerene acceptor. Such non-fullerene acceptors may provide improved OPV performance characteristics such as improved power conversion efficiency, open circuit voltage, fill factor, short circuit current, and/or external quantum efficiency. One example of a non-fullerene acceptor is (4,4,10,10-tetrakis(4-hexylphenyl)-5,11-(2-ethylhexyloxy)-4,10-dihydro-dithienyl[1,2-b:4,5b′]benzodi-thiophene-2,8-diyl) bis(2-(3-oxo-2,3-dihydroinden-5,6-dichloro-1-ylidene) malononitrile.
1. A compound having the structure of Structure I, Structure II, or Structure III:
wherein:
A and B are individually selected from the group consisting of:
each Ar 1 is individually selected from the group consisting of:
each Ar 2 is individually selected from the group consisting of:
each Ar 3 is individually selected from the group consisting of:
each Ar 4 is individually selected from the group consisting of:
M 1 -M 4 are individually selected from the group consisting of hydrogen, fluorine, chlorine, bromine, iodine, astatine, and a cyano group, wherein at least one of M 1 -M 4 is a halogen;
each R is individually a C 1 -C 20 hydrocarbon or an aromatic hydrocarbon;
each X is individually selected from the group consisting of oxygen, carbon, hydrogen, sulfur, selenium, and nitrogen; wherein when X is hydrogen, R is not present;
wherein when X is carbon, the carbon has two additional substituents R; and wherein when X is nitrogen, the nitrogen has one additional substituent R;
each Y is individually selected from the group consisting of:
each m is an integer from 0 to 10; and
each n is an integer from 0 to 10.
2. The compound of claim 1 , wherein each Ar 1 is:
3. The compound of claim 1 , wherein each Ar 3 is:
4. The compound of claim 1 , wherein A or B is:
5. The compound of claim 1 , wherein Ar 4 is:
6. The compound of claim 1 , wherein A or B is:
7. The compound of claim 1 , wherein at least one of M 1 -M 4 is chloride.
8. The compound of claim 1 , wherein each R is 2-ethylhexyl.
9. The compound of claim 1 , wherein each R is selected from the group consisting of:
10. The compound of claim 1 , wherein each Y is:
11. The compound of claim 1 , wherein a length of the compound is at least 25 angstroms.
12. The compound of claim 1 , wherein the compound has one of the following structures C1-C11:
13. The compound of claim 11 , wherein Z 1 , Z 2 , and Z 3 are sulfur.
14. The compound of claim 1 , wherein the compound has one of the following structures:
15. A solar cell comprising the compound of claim 1 .
16. The solar cell of claim 15 , wherein the solar cell has a power conversion efficiency of at least 11%.
17. The solar cell of claim 15 , wherein the solar cell has an open circuit voltage of at least 0.7 Volts.
18. The solar cell of claim 15 , wherein the solar cell has a fill factor of at least 70%.
19. The solar cell of claim 15 , wherein the solar cell has a short circuit current of between 20-25 mA/cm 2 .
20. The solar cell of claim 15 , wherein the solar cell has an external quantum efficiency of at least 75%, as measured between wavelengths of 650-850 nm and providing a transparency window between wavelengths of 400-650 nm.