Polymer solar cell and method of manufacturing the same

1. A polymer solar cell, comprising:

a substrate; and

a first electrode comprising a conductive layer positioned on the substrate;

a hole injection layer positioned on the first electrode;

a photoactive layer positioned on the hole injection layer;

an electron-accepting layer positioned on the photoactive layer;

a buffer layer positioned on the electron-accepting layer; and a second electrode,

wherein the photoactive layer is a blend layer comprising a conductive polymer and an electron acceptor, and wherein an electron-accepting layer comprises a C60-C70 fullerene derivative; and wherein the buffer layer comprises LiF.

2. The polymer solar cell of claim 1 , wherein the electron-accepting layer further comprises PCBM ([6,6]-phenyl-C 61 butyric acid methyl ester).

3. The polymer solar cell of claim 1 , wherein the electron-accepting layer has a thickness of about 0.1 to about 10 nm.

4. The polymer solar cell of claim 1 , wherein the hole injection layer comprises material selected from the group consisting of PEDOT-PSS (poly(3,4-ethylenedioxythiophene))-(poly(styrenesulfonate)), polyaniline-CSA, pentacene, Cu-PC (copper phthalocyanine), P3HT (poly(3-hexylthiophene), polysiloxane carbazole, polyaniline, polyethylene oxide, (poly(1-methoxy-4-(O-disperse Red 1)-2,5-phenylene-vinylene), polyindole, polycarbazole, polypyridiazine, polyisothianaphthalene, polyphenylene sulfide, polyvinylpyridine, polythiophene, polyfluorene, polypyridine, and derivatives thereof, and; a combination comprising at least one of the foregoing.

5. The polymer solar cell of claim 4 , wherein the hole injection layer has a thickness of about 5 to about 2000 nm.

6. The polymer solar cell of claim 1 , wherein the conductive polymer is one or more selected from a group consisting of P3HT (poly(3-hexylthiophene), polysiloxane carbazole, polyaniline, polyethylene oxide, (poly(1-methoxy-4-(O-disperse Red 1)-2,5-phenylene-vinylene), polyindole, polycarbazole, polypyridiazine, polyisothianaphthalene, polyphenylene sulfide, polyvinylpyridine, polythiophene, polyfluorene, polypyridine, and derivatives thereof, and; a combination comprising at least one of the foregoing conductive polymers.

7. The polymer solar cell of claim 1 , wherein the electron acceptor is selected from a group consisting of fullerene or derivatives thereof, nanocrystals, carbon nanotubes, carbon nanorods, carbon nanowires and; a combination comprising at least one of the foregoing electron acceptors.

8. The polymer solar cell of claim 6 , wherein the conductive polymer is P3HT.

9. The polymer solar cell of claim 7 , wherein the electron acceptor is PCBM.

10. The polymer solar cell of claim 1 , wherein the conductive polymer and the electron acceptor are mixed at a weight ratio of about 1:0.8 to about 1:1.2.

11. The polymer solar cell of claim 10 , wherein the conductive polymer and the electron acceptor are mixed at a weight ratio of about 1:0.8.

12. The polymer solar cell of claim 1 , wherein the second electrode comprises metals selected from the group consisting of, including magnesium, calcium, sodium, potassium, titanium, indium, yttrium, lithium, aluminum, silver, tin, lead, and; a combination comprising at least one of the foregoing metals.

13. The polymer solar cell of claim 1 , wherein the second electrode is aluminum.

14. A method of manufacturing a polymer solar cell, comprising:

forming a hole injection layer on a substrate comprising a conductive layer;

forming a photoactive layer on the hole injection layer, wherein the photoactive layer is a blend layer comprising a conductive polymer and an electron acceptor;

performing thermal annealing;

forming an electron-accepting layer on the photoactive layer;

forming a buffer layer on the electron accepting layer; wherein the buffer layer comprises LiF; and

forming a second electrode on the buffer layer.

15. The method of claim 14 , wherein the thermal annealing is performed at about 80 to about 110° C.