Zwitterionic compounds and photovoltaic cells containing same
View Patent ↗Zwitterionic compounds, photovoltaic cell charge carrier layers containing such compounds, photovoltaic cells including such charge carrier layers, and related methods are disclosed.
1. A zwitterionic compound having the formula:
wherein:
R 2 is an anionic moiety that comprises:
R 1 is a cationic heterocyclic moiety, a cationic ammonium moiety, a cationic guanidinium moiety, or a cationic phosphonium moiety;
A is (C(R 3 ) 2 ) n ;
n is zero or greater;
each R 3 is independently H, halo, or a carbon-containing moiety selected from the group consisting of C x alkyl, cycloalkyl, heterocyclyl, C x+1 alkenyl, C x+1 alkynyl and aryl, the carbon-containing moiety optionally being substituted with one or more halo; and
x is at least 1.
2. The zwitterionic compound of claim 1 , wherein n is at least 1.
3. The zwitterionic compound of claim 2 , wherein n is at most 20.
4. The zwitterionic compound of claim 2 , wherein n is at most 10.
5. The zwitterionic compound of claim 2 , wherein n is at most 5.
6. The zwitterionic compound of claim 1 , wherein x is at most 20.
7. The zwitterionic compound of claim 6 , wherein x is at most 15.
8. The zwitterionic compound of claim 6 , wherein x is at most 10.
9. The zwitterionic compound of claim 1 , wherein R 1 comprises a cationic nitrogen-substituted heterocyclic moiety.
10. The zwitterionic compound of claim 9 , wherein the cationic nitrogen-substituted heterocyclic moiety includes at least two nitrogen atoms.
11. The zwitterionic compound of claim 1 , wherein R 1 comprises a cationic substituted ammonium moiety.
12. The zwitterionic compound of claim 11 , wherein the cationic substituted ammonium moiety comprises an alkyl substituted cationic ammonium moiety.
13. The zwitterionic compound of claim 1 , wherein R 1 comprises a cationic substituted guanidinium moiety.
14. The zwitterionic compound of claim 1 , wherein:
R 1 is a cationic nitrogen-substituted heterocyclic moiety, a cationic alkyl substituted ammonium moiety, a cationic guanidinium moiety, or a cationic phosphonium moiety; and
each R 3 is independently H, halo, or a C 1 –C 6 alkyl that is optionally substituted with one or more halo.
15. The zwitterionic compound of claim 1 , wherein:
n is 1–4;
R 1 is an alkyl imidazolium, piperidinium, pyridinium, morpholinium, pyrimidinium, pyridazinium, pyrazinium, pyrazolium, pyrrolinium, thiazolium, oxazolium, triazolium pentalkyl guanidinium, or asymmetric tetraalkylammonium; and
each R 3 is independently H, F, or a C 1 –C 6 alkyl that is optionally substituted with one or more F.
16. The zwitterionic compound of claim 1 , wherein:
n is 1–4;
R 1 is alkyl imidazolium, pyridinium, pyridazinium, or pyrazinium; and
R 3 is a Me that is optionally substituted with one or more F.
17. The zwitterionic compound of claim 1 , wherein:
n is 2 or 3;
R 1 is alkyl imidazolium; and
R 3 is CF 3 .
18. The zwitterionic compound of claim 1 , wherein the compound has the formula:
19. A photovoltaic cell, comprising:
a first electrode;
a second electrode; and
a charge carrier layer between the first and second electrodes, the charge carrier layer comprising:
an electrolyte; and
a zwitterionic compound having the formula:
wherein:
R 2 is an anionic moiety that comprises:
R 1 is a cationic heterocyclic moiety, a cationic ammonium moiety, a cationic guanidinium moiety, or a cationic phosphonium moiety;
A is (C(R 3 ) 2 ) n ;
n is zero or greater;
each R 3 is independently H, halo, or a carbon-containing moiety selected from the group consisting of C x alkyl, cycloalkyl, heterocyclyl, C x+1 alkenyl, C x+1 alkynyl and aryl, the carbon-containing moiety optionally being substituted with one or more halo; and
x is at least 1.
20. The photovoltaic cell of claim 19 , wherein the electrolyte comprises a lithium salt.
21. The photovoltaic cell of claim 19 , further comprising a redox system.
22. The photovoltaic cell of claim 21 , wherein the electrolyte comprises a lithium salt.
23. The photovoltaic cell of claim 21 , wherein the electrolyte and zwitterionic compound form a complex.
24. The photovoltaic cell of claim 23 , wherein the charge carrier layer comprises at least about 10 volume fraction of the complex.
25. The photovoltaic cell of claim 24 , wherein the charge carrier layer comprises at most about 60 volume fraction of the complex.
26. The photovoltaic cell of claim 21 , wherein the charge carrier layer comprises at least about 10 volume fraction of the redox system.
27. The photovoltaic cell of claim 26 , wherein the charge carrier layer comprises at most about 60 volume fraction of the redox system.
28. The photovoltaic cell of claim 21 , further comprising a solvent.
29. The photovoltaic cell of claim 28 , wherein the charge carrier layer comprises at least about five volume fraction of the solvent.
30. The photovoltaic cell of claim 29 , wherein the charge carrier layer comprises at most about 70 volume fraction of the solvent.
31. The photovoltaic cell of claim 19 , further comprising a solvent.
32. The photovoltaic cell of claim 19 , wherein n is at least 1.
33. The photovoltaic cell of claim 32 , wherein n is at most 20.
34. The photovoltaic cell of claim 32 , wherein n is at most 10.
35. The photovoltaic cell of claim 32 , wherein n is at most 5.
36. The photovoltaic cell of claim 19 , wherein x is at most 20.
37. The photovoltaic cell of claim 36 , wherein x is at most 15.
38. The photovoltaic cell of claim 36 , wherein x is at most 10.
39. The photovoltaic cell of claim 19 , wherein R 1 comprises a cationic nitrogen-substituted heterocyclic moiety.
40. The photovoltaic cell of claim 39 , wherein the cationic nitrogen-substituted heterocyclic moiety includes at least two nitrogen atoms.
41. The photovoltaic cell of claim 19 , wherein R 1 comprises a cationic substituted ammonium moiety.
42. The photovoltaic cell of claim 41 , wherein the cationic substituted ammonium moiety comprises a cationic alkyl substituted ammonium moiety.
43. The photovoltaic cell of claim 19 , wherein R 1 comprises a cationic substituted guanidinium moiety.
44. The photovoltaic cell of claim 19 , wherein:
R 1 is a cationic nitrogen-substituted heterocyclic moiety, a cationic alkyl substituted ammonium moiety, a cationic guanidinium moiety, or a cationic phosphonium moiety; and
each R 3 is independently H, halo, or C 1 –C 6 alkyl that is optionally substituted with one or more halo.
45. The photovoltaic cell of claim 19 , wherein:
n is 1–4;
R 1 is an alkyl imidazolium, piperidinium, pyridinium, morpholinium, pyrimidinium, pyridazinium, pyrazinium, pyrazolium, pyrrolinium, thiazolium, oxazolium, triazolium pentalkyl guanidinium, or asymmetric tetraalkylammonium; and
each R 3 is independently H, F, or C 1 –C 6 alkyl that is optionally substituted with one or more F.
46. The photovoltaic cell of claim 19 , wherein:
n is 1–4;
R 1 is alkyl imidazolium, pyridinium, pyridazinium, or pyrazinium; and
R 3 is a Me that is optionally substituted with one or more F.
47. The photovoltaic cell of claim 19 , wherein:
n is 2 or 3;
R 1 is alkyl imidazolium; and
R 3 is CF 3 .
48. The photovoltaic cell of claim 19 , wherein the zwitterionic compound has the formula:
49. The photovoltaic cell of claim 19 , wherein the electrolyte and zwitterionic compound form a complex.
50. The photovoltaic cell of claim 49 , wherein the charge carrier layer comprises at least about 10 volume fraction of the complex.
51. The photovoltaic cell of claim 50 , wherein the charge carrier layer comprises at most about 60 volume fraction of the complex.
52. The photovoltaic cell of claim 49 , further comprising a redox system and a solvent.
53. The photovoltaic cell of claim 52 , wherein the charge carrier layer comprises at least about five volume fraction of the solvent.
54. The photovoltaic cell of claim 53 , wherein the charge carrier layer comprises at most about 70 volume fraction of the solvent.
55. The photovoltaic cell of claim 19 , wherein the charge carrier layer comprises at least about 10 volume fraction of the redox system.
56. The photovoltaic cell of claim 55 , wherein the charge carrier layer comprises at most about 60 volume fraction of the redox system.
57. The photovoltaic cell of claim 19 , further comprising a solvent.