Organic photovoltaic devices

• US 6,657,378 B2
• Filed: 09/06/2001
• Issued: 12/02/2003
• Est. Priority Date: 09/06/2001
• Status: Expired due to Term

• Current Assignee: The Trustees of Princeton University (Princeton University)
• Original Assignee: The Trustees of Princeton University (Princeton University)
• Inventors: Yakimov, Aharon, Forrest, Stephen R.
• Primary Examiner(s): O'Shea, Sandra
• Assistant Examiner(s): Dong, Dalei
• Application Number:
  US09/948,226
• Publication Number:
  US 20030042846A1
• Time in Patent Office: 817 Days
• Field of Search: 213/503, 250/214.1, 250/214.R, 250/208.1, 250/208.2, 250/200, 250/215, 250/214.AL, 257/40
• US Class Current: 313/503
• CPC Class Codes: H10K 2102/103 comprising indium oxides, e.g. ITO
• CPC Class Codes: H10K 30/20 comprising organic-organic junctions, e.g. donor-acceptor junctions
• CPC Class Codes: H10K 30/211 comprising multiple junctions, e.g. double heterojunctions
• CPC Class Codes: H10K 30/57 comprising multiple junctions, e.g. tandem PV cells
• CPC Class Codes: H10K 85/1135 Polyethylene dioxythiophene [PEDOT]; Derivatives thereof
• CPC Class Codes: H10K 85/311 Phthalocyanine
• CPC Class Codes: H10K 85/621 Aromatic anhydride or imide compounds, e.g. perylene tetra-carboxylic dianhydride or perylene tetracarboxylic di-imide
• CPC Class Codes: Y02E 10/549 Organic PV cells

Abstract

The present invention generally relates to organic photosensitive optoelectronic devices. More specifically, it is directed to organic photovoltaic devices, e.g., organic solar cells. Further, it is directed to an optimized organic solar cell comprising multiple stacked subcells in series. High power conversion efficiency are achieved by fabrication of a photovoltaic cell comprising multiple stacked subcells with thickness optimization and employing an electron blocking layer.

Claims

1. An organic photosensitive optoelectronic device comprising:

an anode;

multiple subcells in series, each subcell comprising;

an electron donor layer, and

an electron acceptor layer in contact with the electron donor layer,

an electron-hole recombination zone separating the subcells, and

a cathode,

wherein the current generated by each subcell is about equal.

2. The device of claim 1, wherein an exciton blocking layer is situated between the electron acceptor layer and the cathode.

3. The device of claim 2, wherein the exciton blocking layer comprises BCP.

4. The device of claim 2, wherein the exciton blocking layer comprises Alq₂OPH.

5. The device of claim 1, wherein the an anode smoothing layer is situated between the electron donor layer and the anode.

6. The device of claim 1, wherein the anode smoothing layer comprises PEDOT.

7. The device of claim 1, wherein the electron donor layer comprises a pthalocyanine or a porphyrin, and the electron acceptor layer comprises a perylene, naphthalene, fullerene or nanotubule.

8. The device of claim 1, wherein the anode is selected from transparent conducting oxides.

9. The device of claim 8, wherein the anode is selected from ITO.

10. The device of claim 1, wherein the electron-hole recombination zone is a semitransparent metal layer.

11. The device of claim 1, wherein the electron-hole recombination zone is selected from a layer of Ag, Li, LiF, Al, Ti, and Sn.

12. The device of claim 11, wherein the electron-hole recombination zone a layer of Ag.

13. The device of claim 1, wherein the electron-hole recombination zone is less than about 20 Å

in thickness.

14. The device of claim 10, wherein the metal layer is composed of nanoparticles.

15. The device of claim 1, wherein the electron-hole recombination zone comprises a region of electronically active defects.

16. The device of claim 2, wherein:

the electron transport layer is PTCBI

the hole transport layer is CuPc;

the electron-hole recombination zone is Ag, and

the exciton blocking layer is BCP.

17. The device of claim 1, wherein the external power conversion efficiency is at least 1% at one sun illumination.

18. The device of claim 1, wherein the device is capable of a power conversion efficiency of about 2.5% at a light intensity of about 0.5 sun.