Solar cells
Organic photosensitive optoelectronic devices are disclosed. The devises are thin-film crystalline organic optoelectronic devices capable of generating a voltage when exposed to light, and prepared by a method including the steps of: depositing a first organic layer over a first electrode; depositing a second organic layer over the first organic layer; depositing a confining layer over the second organic layer to form a stack; annealing the stack; and finally depositing a second electrode over the second organic layer.
1. A method for making an organic photosensitive optoelectronic device comprising the steps of:
(a) depositing a first organic layer over a first electrode;
(b) depositing a second organic layer over the first organic layer;
(c) depositing a confining layer over the second organic layer to form a stack;
(d) annealing the stack; and
(e) depositing a second electrode over the second organic layer, wherein the device is capable of generating a voltage when exposed to light, wherein said confining layer prevents formation of a rough surface morphology while allowing formation of a bulk heterojunction with an interpenetrating donor-acceptor network between the first and second organic layers during said annealing step.
2. The method of claim 1 , wherein the first organic layer is a donor layer.
3. The method of claim 1 , wherein the second organic layer is an acceptor layer.
4. The method of claim 1 , wherein the annealing is carried out by irradiation with light having a wavelength of from about 400 nm to about 700 nm.
5. The method of claim 1 , further comprising depositing a third organic layer over the second organic layer.
6. The method of claim 4 , wherein the third organic layer is an exciton blocking layer.
7. The method of claim 1 , wherein the device further comprises at least one crystalline domain in the organic layers after the annealing step.
8. The method of claim 7 , wherein the crystalline domain is from about 0.5 nm to about 100 nm.
9. The method of claim 7 , further comprising depositing a third organic layer over the second organic layer.
10. The method of claim 1 , wherein the annealing is carried out at a temperature of from about 340K to about 600K.
11. The method of claim 10 , wherein the annealing is carried out at a temperature of about 560K.
12. The method of claim 10 , wherein the annealing is carried out at a pressure less than about 10 mTorr.
13. The method of claim 12 , wherein the annealing is carried out in a vacuum or inert gas atmosphere.
14. The method of claim 1 , wherein the annealing is carried out for a time of from about 5 seconds to about 30 minutes.
15. The method of claim 14 , wherein the annealing is carried out for a time of about 15 minutes.
16. The method of claim 14 , wherein the annealing is carried out for a time of about 2 minutes.
17. A method for making an organic photosensitive optoelectronic device comprising the steps of:
(a) depositing a first organic layer over a first electrode;
(b) depositing a second organic layer over the first organic layer;
(c) depositing a confining layer over the second organic layer to form a stack;
(d) annealing the stack;
(e) removing the confining layer; and
(f) depositing a second electrode over the second organic layer, wherein the device is capable of generating a voltage when exposed to light.
18. The method of claim 17 , further comprising:
depositing an exciton blocking layer over the second organic layer after removing the confining layer; and
annealing the stack after depositing the second electrode.
19. The method of claim 17 , wherein the device farther comprises at least one crystalline domain in the organic layers after the annealing step.
20. The method of claim 19 , further comprising:
depositing an exciton blocking layer over the second organic layer after removing the confining layer; and
annealing the stack after depositing the second electrode.