Semiconductor-nanocrystal/conjugated polymer thin films
View Patent ↗The invention described herein provides for thin films and methods of making comprising inorganic semiconductor-nanocrystals dispersed in semiconducting-polymers in high loading amounts. The invention also describes photovoltaic devices incorporating the thin films.
1. A thin film capable of use in a photovoltaic device, the thin film comprising:
a semiconducting conjugated polymer having at least 5 wt % semiconductor-nanocrystals embedded therein, wherein:
at least a portion of the semiconductor-nanocrystals have an aspect ratio greater than about 2, and wherein the thin film is capable of providing a power conversion efficiency greater than 2% at A.M. 1.5 global illumination when in the photovoltaic device.
2. The thin film of claim 1 , wherein: the semiconducting conjugated polymer has between about 5 and about 99 wt % of semiconductor-nanocrystals embedded therein.
3. The thin film of claim 1 , wherein: the semiconducting conjugated polymer has between about 20 and 95 wt % semiconductor-nanocrystals embedded therein.
4. The thin film of claim 1 , wherein: the semiconducting conjugated polymer has between about 50 and 95 wt % semiconductor-nanocrystals embedded therein.
5. The thin film of claim 1 , wherein: the semiconducting conjugated polymer has about 90 wt % semiconductor-nanocrystals embedded therein.
6. The thin film of claim 1 , wherein: the semiconducting conjugated polymer is chosen from the group consisting of trans-polyacetylenes, polypyrroles, polythiophenes, polyanilines, poly(p-phenylene)s and polyp-phenylene-vinylene)s, polyfluorenes, polyaromatic amines, poly(thienylene-vinylene)s and soluble derivatives thereof.
7. The thin film of claim 6 , wherein: the conjugated polymer is chosen from the group consisting of (poly(2-methoxy 5-(2′-ethylhexyloxy)p-phenylenevinylene)(MEH-PPV) and poly(3-hexylthiophene, (P3HT).
8. The thin film of claim 1 , wherein: the semiconductor-nanocrystals comprise rods having a length of greater than about 20 nm.
9. The thin film of claim 1 , wherein: the semiconductor-nanocrystals comprise rods having a length of between about 20 nm and about 200 nm.
10. The thin film of claim 9 , wherein: the semiconductor-nanocrystals comprise rods having a length of between about 60 nm and about 110 nm.
11. The thin film of claim 1 , wherein: the semiconductor-nanocrystals comprise rods that are about 7 nm×60 nm.
12. The thin film of claim 1 , wherein: the semiconductor-nanocrystals comprise a semiconductor selected from the group consisting of Group II-VI, Group III-V, Group IV semiconductors and tertiary chalcopyrites.
13. The thin film of claim 12 , wherein: the semiconductor-nanocrystals are selected from the group consisting of CdSe, CdTe, InP, GaAs, CuInS 2 , CuInSe 2 , AlGaAs, InGaAs, Ge and Si.
14. The thin film of claim 1 , wherein the semiconductor-nanocrystals are selected from the group consisting of CdSe and CdTe.
15. The thin film of claim 1 , wherein: a portion of the semiconductor-nanocrystals are branched nanocrystals.
16. The thin film of claim 15 , wherein: a portion of the branched nanocrystals have at least two arms, said arms are not all the same length.
17. The thin film of claim 15 , wherein: the branched nanocrystals do not all have the same shape.
18. The thin film of claim 15 , wherein: the branched nanocrystals have 4 arms and have a tetrahedral symmetry.
19. The thin film of claim 18 , wherein: the branched nanocrystals are either CdSe or CdTe and are embedded in an amount of about 90 wt %.
20. The thin film of claim 1 , wherein: the film has a thickness of from about from about 100 nm to about 350 nm.
21. The thin film of claim 18 , wherein: the film has a thickness of about 200 nm.
22. A photovoltaic device, comprising: the thin film of claim 1 .
23. The photovoltaic device of claim 22 , wherein: at least a portion of the semiconductor-nanocrystals have an aspect ratio greater than about 5.
24. The photovoltaic device of claim 22 , wherein: at least a portion of the semiconductor-nanocrystals have an aspect ratio greater than about 10.
25. The photovoltaic device of claim 22 , wherein: at least a portion of the semiconductor-nanocrystals have an aspect ratio of between about 5 and about 50.
26. The photovoltaic device of claim 22 , wherein: at least a portion of the semiconductor-nanocrystals have an aspect ratio of between about 2 and about 10.
27. The photovoltaic device of claim 22 , wherein: the semiconducting conjugated polymer has between about 5 and about 99 wt % of semiconductor-nanocrystals embedded therein.
28. The photovoltaic device of claim 22 , wherein: the semiconducting conjugated polymer has between about 20 and 95 wt % semiconductor-nanocrystals embedded therein.
29. The photovoltaic device of claim 22 , wherein: the semiconducting conjugated polymer has between about 50 and 95 wt % semiconductor-nanocrystals embedded therein.
30. The photovoltaic device of claim 22 , wherein: the semiconducting conjugated polymer has about 90 wt % semiconductor-nanocrystals embedded therein.
31. The photovoltaic device of claim 22 , wherein: the semiconducting conjugated polymer is chosen from the group consisting of trans-polyacetylenes, polypyrroles, polythiophenes, polyanilines, poly(p-phenylene)s and poly(p-phenylene-vinylene)s, polyfluorenes, polyaromatic amines, poly(thienylene-vinylene)s and soluble derivatives thereof.
32. The photovoltaic device of claim 31 , wherein: the conjugated polymer is chosen from the group consisting of (poly(2-methoxy5-(2′-ethylhexyloxy-)p-phenylenevinylene)(MEH-PPV) and poly(3-hexylthiophene, (P3HT).
33. The photovoltaic device of claim 22 , wherein: the semiconductor-nanocrystals comprise rods having a length of greater than about 20 nm.
34. The photovoltaic device of claim 22 , wherein: the semiconductor-nanocrystals comprise rods having a length of between about 20 nm and about 200 nm.
35. The photovoltaic device of claim 34 , wherein: the semiconductor-nanocrystals comprise rods having a length of between about 60 nm and about 110 nm.
36. The photovoltaic device of claim 22 , wherein: the semiconductor-nanocrystals comprise rods that are about 7 nm×60 nm.
37. The photovoltaic device of claim 22 , wherein: the semiconductor-nanocrystals comprise a semiconductor selected from the group consisting of Group II-VI, Group III-V, Group IV semiconductors and tertiary chalcopyrites.
38. The photovoltaic device of claim 37 , wherein: the semiconductor-nanocrystals are selected from the group consisting of CdSe, CdTe, InP, GaAs, CuInS 2 , CuInSe 2 , AlGaAs, InGaAs, Ge and Si.
39. The photovoltaic device of claim 22 , wherein: the semiconductor-nanocrystals are selected from the group consisting of CdSe and CdTe.
40. The photovoltaic device of claim 22 , wherein: a portion of the semiconductor-nanocrystals are branched nanocrystals.
41. The photovoltaic device of claim 40 , wherein: a portion of the branched nanocrystals have at least two arms, said arms are not all the same length.
42. The photovoltaic device of claim 40 , wherein: the branched nanocrystals do not all have the same shape.
43. The photovoltaic device of claim 40 , wherein: the branched nanocrystals have 4 arms and have a tetrahedral symmetry.
44. The photovoltaic device of claim 43 , wherein: the branched nanocrystals are either CdSe or CdTe and are embedded in an amount of about 90 wt %.
45. The photovoltaic device of claim 22 , wherein: the film has a thickness of from about from about 100 nm to about 350 nm.
46. The photovoltaic device of claim 45 , wherein: the film has a thickness of about 200 nm.