Photoactive polymers

1. An article, comprising:

a first electrode;

a second electrode; and

a photoactive material between the first and second electrodes, the photoactive material comprising a polymer including first, second, and third comonomer repeat units, the first comonomer repeat unit comprising a silacyclopentadithiophene moiety, the second comonomer repeat unit comprising a cyclopentadithiophene moiety, and the third comonomer repeat unit comprising a benzothiadiazole moiety;

wherein the article is configured as a photovoltaic cell.

2. The article of claim 1 , wherein the molar ratio of the first and second comonomer repeat units is at most about 5:1.

3. The article of claim 1 , wherein the molar ratio of the first and second comonomer repeat units is at least about 1:1.

4. The article of claim 1 , wherein the molar ratio of the first and second comonomer repeat units is about 3:1.

5. The article of claim 1 , wherein the first comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula (1):

in which each of R 1 , R 2 , R 3 , and R 4 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

6. The article of claim 5 , wherein each of R 1 and R 2 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl.

7. The article of claim 6 , wherein each of R 1 and R 2 , independently, is C 1 -C 20 alkyl.

8. The article of claim 7 , wherein each of R 1 and R 2 is 2-ethylhexyl.

9. The article of claim 1 , wherein the second comonomer repeat unit comprises a cyclopentadithiophene moiety of formula (2):

in which each of R 1 , R 2 , R 3 , and R 4 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

10. The article of claim 9 , wherein each of R 1 and R 2 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl.

11. The article of claim 10 , wherein each of R 1 and R 2 , independently, is C 1 -C 20 alkyl.

12. The article of claim 11 , wherein each of R 1 and R 2 is 2-ethylhexyl.

13. The article of claim 1 , wherein the third comonomer repeat unit comprises a benzothiadiazole moiety of formula (3):

in which each of R 1 and R 2 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

14. The article of claim 13 , wherein each of R 1 and R 2 , independently, is H.

15. The article of claim 1 , wherein the polymer is an electron donor material.

16. The article of claim 15 , wherein the article further comprises an electron acceptor material.

17. The article of claim 16 , wherein the electron acceptor material comprises a material selected from the group consisting of fullerenes, inorganic nanoparticles, oxadiazoles, discotic liquid crystals, carbon nanorods, inorganic nanorods, polymers containing CN groups, polymers containing CF 3 groups, and combinations thereof.

18. The article of claim 17 , wherein the electron acceptor material comprises a substituted fullerene.

19. The article of claim 18 , wherein the substituted fullerene comprises C61-PCBM or C71-PCBM.

20. The article of claim 1 , wherein the article has an efficiency of at least about 4 under AM 1.5 conditions.

21. The article of claim 1 , wherein the article has an efficiency of at least about 5 under AM 1.5 conditions.

22. A polymer, comprising:

first, second, and third comonomer repeat units, the first comonomer repeat unit comprising a silacyclopentadithiophene moiety, the second comonomer repeat unit comprising a cyclopentadithiophene moiety, and the third comonomer repeat unit comprising a benzothiadiazole moiety.

23. The polymer of claim 22 , wherein the molar ratio of the first and second comonomer repeat units is at most about 5:1.

24. The polymer of claim 22 , wherein the molar ratio of the first and second comonomer repeat units is at least about 1:1.

25. The polymer of claim 22 , wherein the molar ratio of the first and second comonomer repeat units is about 3:1.

26. The polymer of claim 22 , wherein the first comonomer repeat unit comprises a silacyclopentadithiophene moiety of formula (1):

in which each of R 1 , R 2 , R 3 , and R 4 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

27. The article of claim 26 , wherein each of R 1 and R 2 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl.

28. The polymer of claim 27 , wherein each of R 1 and R 2 , independently, is C 1 -C 20 alkyl.

29. The polymer of claim 28 , wherein each of R 1 and R 2 is 2-ethylhexyl.

30. The polymer of claim 22 , wherein the second comonomer repeat unit comprises a cyclopentadithiophene moiety of formula (2):

in which each of R 1 , R 2 , R 3 , and R 4 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

31. The article of claim 30 , wherein each of R 1 and R 2 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl.

32. The polymer of claim 31 , wherein each of R 1 and R 2 , independently, is C 1 -C 20 alkyl.

33. The polymer of claim 32 , wherein each of R 1 and R 2 is 2-ethylhexyl.

34. The polymer of claim 22 , wherein the third comonomer repeat unit comprises a benzothiadiazole moiety of formula (3):

in which each of R 1 and R 2 , independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

35. The polymer of claim 34 , wherein each of R 1 and R 2 , independently, is H.

36. The article of claim 1 , wherein the polymer is of the following formula:

in which

each of m and n, independently, is an integer greater than 1;

each of R 1 , R 2 , R 3 , and R 4 in the silacyclopentadithiophene moiety, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl;

each of R 1 , R 2 , R 3 , and R 4 in the cyclopentadithiophene moiety, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl; and

each of R 1 and R 2 in the benzothiadiazole moiety, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

37. The article of claim 36 , wherein each of R 1 and R 2 in the silacyclopentadithiophene moiety, independently, is C 1 -C 20 alkyl; each of R 3 and R 4 in the silacyclopentadithiophene moiety is H; each of R 1 and R 2 in the cyclopentadithiophene moiety, independently, is C 1 -C 20 alkyl; each of R 3 and R 4 in the cyclopentadithiophene moiety is H; and each of R 1 and R 2 in the benzothiadiazole moiety is H.

38. The article of claim 37 , wherein the polymer is

39. The polymer of claim 22 , wherein the polymer is of the following formula:

in which

each of m and n, independently, is an integer greater than 1;

each of R 1 , R 2 , R 3 , and R 4 in the silacyclopentadithiophene moiety, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl;

each of R 1 , R 2 , R 3 , and R 4 in the cyclopentadithiophene moiety, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl; and

each of R 1 and R 2 in the benzothiadiazole moiety, independently, is H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, C 3 -C 20 cycloalkyl, C 1 -C 20 heterocycloalkyl, aryl, heteroaryl, halo, CN, OR, C(O)R, C(O)OR, or SO 2 R; R being H, C 1 -C 20 alkyl, C 1 -C 20 alkoxy, aryl, heteroaryl, C 3 -C 20 cycloalkyl, or C 1 -C 20 heterocycloalkyl.

40. The polymer of claim 39 , wherein each of R 1 and R 2 in the silacyclopentadithiophene moiety, independently, is C 1 -C 20 alkyl; each of R 3 and R 4 in the silacyclopentadithiophene moiety is H; each of R 1 and R 2 in the cyclopentadithiophene moiety, independently, is C 1 -C 20 alkyl; each of R 3 and R 4 in the cyclopentadithiophene moiety is H; and each of R 1 and R 2 in the benzothiadiazole moiety is H.

41. The polymer of claim 40 , wherein the polymer is