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Organic and nano-structured composite photovoltaics: An overview

Published online by Cambridge University Press:  01 December 2005

Sophie E. Gledhill ,
Brian Scott  and
Brian A. Gregg
Sophie E. Gledhill*
Affiliation:
National Renewable Energy Laboratory, Golden, Colorado 80401
Brian Scott
Affiliation:
National Renewable Energy Laboratory, Golden, Colorado 80401
Brian A. Gregg
Affiliation:
National Renewable Energy Laboratory, Golden, Colorado 80401
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Organic photovoltaic devices are poised to fill the low-cost, low power niche in the solar cell market. Recently measured efficiencies of solid-state organic cells are nudging 5% while Grätzel’s more established dye-sensitized solar cell technology is more than double this. A fundamental understanding of the excitonic nature of organic materials is an essential backbone for device engineering. Bound electron-hole pairs, “excitons,” are formed in organic semiconductors on photo-absorption. In the organic solar cell, the exciton must diffuse to the donor–accepter interface for simultaneous charge generation and separation. This interface is critical as the concentration of charge carriers is high and recombination here is higher than in the bulk. Nanostructured engineering of the interface has been utilized to maximize organic materials properties, namely to compensate the poor exciton diffusion lengths and lower mobilities. Excitonic solar cells have different limitations on their open-circuit photo-voltages due to these high interfacial charge carrier concentrations, and their behavior cannot be interpreted as if they were conventional solar cells. This article briefly reviews some of the differences between excitonic organic solar cells and conventional inorganic solar cells and highlights some of the technical strategies used in this rapidly progressing field, whose ultimate aim is for organic solar cells to be a commercial reality.

Keywords

NanoscaleOrganicPhotoconductivity
Type
Reviews—Energy and The Environment Special Section
Information
Journal of Materials Research , Volume 20 , Issue 12 , December 2005 , pp. 3167 - 3179
Copyright
Copyright © Materials Research Society 2005

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References

REFERENCES

1.Alsema, E.A.: Energy pay-back time and CO2 emissions of PV systems. Prog. Photovoltaics 8, 17 (2000).3.0.CO;2-C>CrossRefGoogle Scholar
2.Hung, L.S. and Chen, C.H.: Recent progress of molecular organic electroluminescent materials and devices. Mater. Sci. Eng. R 39, 143 (2002).CrossRefGoogle Scholar
3.Patel, N.K., Cina, S. and Burroughes, J.H.: High-efficiency organic light-emitting diodes. IEEE J. Sel. Top. Quant. 8, 346 (2002).CrossRefGoogle Scholar
4.Neumann, R. and Davidov, D.: Layered assemblies and electroluminescence in poly(arylenevinylene)-type conjugated polymers. Acta Polym. 49, 642 (1998).3.0.CO;2-G>CrossRefGoogle Scholar
5.Burrows, P.E., Gu, G., Bulovic, V., Shen, Z., Forrest, S.R. and Thompson, M.E.: Achieving full-color organic light-emitting devices for lightweight, flat-panel displays. IEEE Electron Dev. 44, 1188 (1997).CrossRefGoogle Scholar
6.Gregg, B.A.: The photoconversion mechanism of excitonic solar cells. MRS Bull. 30(2005).CrossRefGoogle Scholar
7.Gregg, B.A.: Excitonic solar cells. J. Phys. Chem. B 107, 4688 (2003).CrossRefGoogle Scholar
8.Gregg, B.A.: Coulomb forces in excitonic solar cells, in Organic Photovoltaics, edited by Sun, S.S. and Sariciftci, N.S. (Marcell Dekker, New York, 2005), p. 139.Google Scholar
9.Gregg, B.A.: Excitonic solar cells: The physics and chemistry of organic-based photovoltaics. Molecules Comp. Electron. Dev. 844, 243 (2003).Google Scholar
10.Gregg, B.A. and Hanna, M.C.: Comparing organic to inorganic photovoltaic cells: Theory, experiment, and simulation. J. Appl. Phys. 93, 3605 (2003).CrossRefGoogle Scholar
11.Green, M.A.: Solar Cells: Operating Principles, Technology and Systems Applications, 1st ed. (The University of New South Wales, Sydney, Australia, 1986).Google Scholar
12.Sze, S.M., Physics of Semiconductor Devices, 2nd ed. (Wiley-Interscience, New York, 1981).Google Scholar
13.Fahrenbruch, A.L. and Bube, R.H.: Fundamentals of Solar Cells: Photovoltaic Energy Conversion (Academic Press, New York, 1983).Google Scholar
14.Grätzel, M.: Perspectives for dye-sensitized nanocrystalline solar cells. Prog. Photovoltaics 8, 171 (2000).3.0.CO;2-U>CrossRefGoogle Scholar
15.O’Regan, B. and Gratzel, M.: A low-cost, high efficiency solar cell based on dye-sensitized colloidal TiO2 films. Nature 353, 737 (1991).CrossRefGoogle Scholar
16.O’Regan, B., Moser, J., Anderson, M. and Gratzel, M.: Vectorial electron injection into transparent semiconductor membranes and electric-field effects on the dynamics of light-induced charge separation. J. Phys. Chem. 94, 8720 (1990).CrossRefGoogle Scholar
17.Nazeeruddin, M.K., Kay, A., Rodicio, I., Humphrybaker, R., Muller, E., Liska, P., Vlachopoulos, N. and Gratzel, M.: Conversion of light to electricity by cis-X2bis(2,2′-bipyridyl-4,4′-dicarboxylate)ruthenium(Ii) charge-transfer sensitizers (X = Cl-, Br-, I-, Cn-, And Scn-) on nanocrystalline TiO2 electrodes. J. Am. Chem. Soc. 115, 6382 (1993).CrossRefGoogle Scholar
18.Tang, C.W.: 2-layer organic photovoltaic cell. Appl. Phys. Lett. 48, 183 (1986).CrossRefGoogle Scholar
19.Waldauff, C., Schilinsky, P., Hauch, J. and Brabec, C.J.: Material and device concepts for organic photovoltaics: towards competitive efficiencies. Thin Solid Films 451–452, 503 (2004).CrossRefGoogle Scholar
20.Peumans, P., Uchida, S. and Forrest, S.R.: Efficient bulk heterojunction photovolataic cells using small-molecular-weight organic thin films. Nature 425, 158 (2003).CrossRefGoogle ScholarPubMed
21.Green, M.A.: Solar cell efficiency tables (Version 25). Prog. Photovoltaics 13, 49 (2005).CrossRefGoogle Scholar
22.Hinsch, A., Kroon, J., Rainer, K., Sasrawan, R., Meyer, A. and Uhlendorf, I.: In Long-term stability and efficiency of dye-sensitized solar cells (Munich, Germany, 2001), p. 51.Google Scholar
23.Komiya, R., Han, L.Y., Yamanaka, R., Islam, A. and Mitate, T.: Highly efficient quasi-solid state dye-sensitized solar cell with ion conducting polymer electrolyte. J. Photochem. Photobio. A 164, 123 (2004).CrossRefGoogle Scholar
24.Kumara, G.R.R.A., Konno, A., Shiratsuchi, K., Tsukahara, J. and Tennakone, K.: Dye-sensitized solid state solar cells: Use of crystal growth inhibitors for the deposition of the hole collector. Chem. Mater. 14, 945 (2002).CrossRefGoogle Scholar
25.Kumara, G.R.R.A., Kaneko, S., Okuya, M. and Tennakone, K.: Fabrication of solid state dye-sensitized solar cells using triethylamine hydrothiocyanate as a CuI crystal growth inhibitor. Langmuir 18, 10493 (2002).CrossRefGoogle Scholar
26.Meng, Q.B., Takahashi, K., Zhang, X.T., Sutanto, I., Rao, T.N., Sato, O., Fujishima, A., Watanabe, H., Nakamort, T. and Urangami, M.: Fabrication of an efficient solid state dye-sensitized solar cell. Langmuir 19, 3572 (2003).CrossRefGoogle Scholar
27.O’Regan, B., Lenzmann, F., Muis, R. and Wienke, J.: A solid-state dye-sensitized solar cell fabricated with pressure-treated P25-TiO2 and CuSCN: Analysis of pore filling and IV characteristics. Chem. Mater. 14, 5023 (2002).CrossRefGoogle Scholar
28.Grätzel, M.: Dye-sensitized solid-state heterjunction solar cells. MRS Bull. 30, 23 (2005).CrossRefGoogle Scholar
29.Schmidt-Mende, L., Zakeeruddin, S.M. and Grätzel, M.: Efficiency improvement in solid state dye sensitized photovoltaics with an amphilic Ruthenium dye. Appl. Phys. Lett. 86, 013504 (2005).CrossRefGoogle Scholar
30.Gosh, A.K. and Feng, T.: Merocyanine organic solar cells. J. Appl. Phys. 49, 5982 (1978).CrossRefGoogle Scholar
31.Xue, J.G., Rand, B.P., Uchida, S. and Forrest, S.R.: A hybrid planar-mixed molecular heterojunction photovoltaic cell. Adv. Mater. 17, 66 (2005).CrossRefGoogle Scholar
32.Forrest, S.R.: The limits to organic photovoltaic cell efficiency. MRS Bull. 30, 28 (2005).CrossRefGoogle Scholar
33.Xue, J.G., Uchida, S., Rand, B.P. and Forrest, S.R.: Asymmetric tandem organic photovoltaic cells with hybrid planar-mixed molecular heterojunctions. Appl. Phys. Lett. 85, 5757 (2004).CrossRefGoogle Scholar
34.Sun, B.Q., Snaith, H.J., Dhoot, A.S., Westenhoff, S., and Greenham, N.C.: Vertically segregated hybrid blends for photovoltaic devices with improved efficiency. J. Appl. Phys. 97 (2005).Google Scholar
35.Huynh, W.U., Dittmer, J.J. and Alivisatos, A.P.: Hybrid nanorod-polymer solar cells. Science 295, 2425 (2002).CrossRefGoogle ScholarPubMed
36.Milliron, D.J., Gur, I. and Alivisatos, A.P.: Hybrid organic– manocrystal solar cells. MRS Bull. 30, 41 (2005).CrossRefGoogle Scholar
37.Chen, S-G., Gregg, B.A. and Stradins, P.: Doping highly ordered organic semiconductors: Experimental results and fits to a self-consistent model of excitonic processes, doping and transport. J. Phys. Chem. B. 2005 , (in press).Google ScholarPubMed
38.Gregg, B.A., Chen, S.G. and Cormier, R.A.: Coulomb forces and doping in organic semiconductors. Chem. Mater. 16, 4586 (2004).CrossRefGoogle Scholar
39.Hagfeldt, A. and Gratzel, M.: Molecular photovoltaics. Accounts Chem. Res. 33, 269 (2000).CrossRefGoogle ScholarPubMed
40.Simon, J. and Andre, J-J.: Molecular Semiconductors (Springer Verlag, Berlin, 1985).CrossRefGoogle Scholar
41.Gregg, B.A.: Bilayer molecular solar cells on spin-coated TiO2 substrates. Chem. Phys. Lett. 258, 376 (1996).CrossRefGoogle Scholar
42.Gregg, B.A., Fox, M.A. and Bard, A.J.: Photovoltaic effect in symmetrical cells of a liquid-crystal porphyrin. J. Phys. Chem. 94, 1586 (1990).CrossRefGoogle Scholar
43.Gregg, B.A.: The essential interface: Studies in dye-sensitized solar cells, in Semiconductor Photochemistry and Photophysics ; Vol. 10, edited by Schanze, K.S. and Ramamurthy, V. (Marcel Dekker, New York, 2002), p. 51.Google Scholar
44.Gregg, B.A.: Photovoltaic properties of a molecular semiconductor modulated by an exciton-dissociating film. Appl. Phys. Lett. 67, 1271 (1995).CrossRefGoogle Scholar
45.Pope, M. and Swenberg, C.E.: Electronic Processes in Organic Crystals and Polymers, 2nd ed. (Oxford University Press, New York, 1999).CrossRefGoogle Scholar
46.Gregg, B.A., Sprague, J. and Peterson, M.W.: Long-range singlet energy transfer in perylene bis(phenethylimide) films. J. Phys. Chem. B 101, 5362 (1997).CrossRefGoogle Scholar
47.Popovic, Z.D., Hor, A.M. and Loutfy, R.O.: A study of carrier generation mechanism in benzimidazole perylene tetraphenyldiamine thin-film structures. Chem. Phys. 127, 451 (1988).CrossRefGoogle Scholar
48.Zakhidov, A.A. and Yoshino, K.: Polarization double barriers at the interfaces in organic multilayered structures and superlattices. Synth. Met. 64, 155 (1994).CrossRefGoogle Scholar
49.Kenkre, V.M., Parris, P.E. and Schmid, D.: Investigation of the appropriateness of sensitized luminescence to determine exciton motion parameters in pure molecular-crystals. Phys. Rev. B 32, 4946 (1985).CrossRefGoogle ScholarPubMed
50.Wang, Y. and Suna, A.: Fullerenes in photoconductive polymers; Charge generation and charge transport. J. Phys. Chem. B 101, 5627 (1997).CrossRefGoogle Scholar
51.Gregg, B.A., Pichot, F., Ferrere, S. and Fields, C.L.: Interfacial recombination processes in dye-sensitized solar cells and methods to passivate the interfaces. J. Phys. Chem. B 105, 1422 (2001).CrossRefGoogle Scholar
52.Moser, J.E. and Gratzel, M.: Observation of temperature independent heterogeneous electron-transfer reactions in the inverted marcus region. Chem. Phys. 176, 493 (1993).CrossRefGoogle Scholar
53.Haque, S.A., Tachibana, Y., Klug, D.R. and Durrant, J.R.: Charge recombination kinetics in dye-sensitized nanocrystalline titanium dioxide films under externally applied bias. J. Phys. Chem. B 102, 1745 (1998).CrossRefGoogle Scholar
54.Salafsky, J.S., Lubberhuizen, W.H., van Faassen, E. and Schropp, R.E.I.: Charge dynamics following dye photoinjection into a TiO2 nanocrystalline network. J. Phys. Chem. B. 102, 766 (1998).CrossRefGoogle Scholar
55.Haque, S.A., Tachibana, Y., Willis, R.L., Moser, J.E., Gratzel, M., Klug, D.R. and Durrant, J.R.: Parameters influencing charge recombination kinetics in dye-sensitized nanocrystalline titanium dioxide films. J. Phys. Chem. B 104, 538 (2000).CrossRefGoogle Scholar
56.Pichot, F. and Gregg, B.A.: The photovoltage-determining mechanism in dye-sensitized solar cells. J. Phys. Chem. B 104, 6 (2000).CrossRefGoogle Scholar
57.Nelson, J., Kirkpatrick, J. and Ravirajan, P.: Factors limiting the efficiency of molecular photovoltaic devices. Phys. Rev. B 69, 035337 (2004).CrossRefGoogle Scholar
58.Ramsdale, C.M., Barker, J.A., Arias, A.C., MacKenzie, J.D., Friend, R.H. and Greenham, N.C.: The origin of the open-circuit voltage in polyfluorene-based photovoltaic devices. J. Appl. Phys. 92, 4266 (2002).CrossRefGoogle Scholar
59.Tan, S.X., Zhai, J., Wan, M.X., Meng, Q.B., Li, Y.L., Jiang, L. and Zhu, D.B.: Influence of small molecules in conducting polyaniline on the photovoltaic properties of solid-state dye-sensitized solar cells. J. Phys. Chem. B 108, 18693 (2004).CrossRefGoogle Scholar
60.Ferrere, S. and Gregg, B.A.: Photosensitization of TiO2 by [Fe-II(2,2′-bipyridine-4,4′-dicarboxylic acid)(2)(CN)(2)]: Band selective electron injection from ultra-short-lived excited states. J. Am. Chem. Soc. 120, 843 (1998).CrossRefGoogle Scholar
61.Tachibana, Y., Moser, J.E., Gratzel, M., Klug, D.R. and Durrant, J.R.: Subpicosecond interfacial charge separation in dye-sensitized nanocrystalline titanium dioxide films. J. Phys. Chem. 100, 20056 (1996).CrossRefGoogle Scholar
62.Asbury, J.B., Ellingson, R.J., Ghosh, H.N., Ferrere, S., Nozik, A.J. and Lian, T.Q.: Femtosecond IR study of excited-state relaxation and electron-injection dynamics of Ru(dcbpy)(2)(NCS)(2) in solution and on nanocrystalline TiO2 and Al2O3 thin films. J. Phys. Chem. B 103, 3110 (1999).CrossRefGoogle Scholar
63.Nelson, J.: Continuous-time random-walk model of electron transport in nanocrystalline TiO2 electrodes. Phys. Rev. B 59, 15374 (1999).CrossRefGoogle Scholar
64.Kopidakis, N., Schiff, E.A., Park, N.G., van Lagemaat, J. de and Frank, A.J.: Ambipolar diffusion of photocarriers in electrolyte-filled, nanoporous TiO2. J. Phys. Chem. B 104, 3930 (2000).CrossRefGoogle Scholar
65.Papageorgiou, N., Barbe, C. and Gratzel, M.: Morphology and adsorbate dependence of ionic transport in dye sensitized mesoporous TiO2 films. J. Phys. Chem. B 102, 4156 (1998).CrossRefGoogle Scholar
66.Cahen, D., Hodes, G., Gratzel, M., Guillemoles, J.F. and Riess, I.: Nature of photovoltaic action in dye-sensitized solar cells. J. Phys. Chem. B 104, 2053 (2000).CrossRefGoogle Scholar
67.Hodes, G., Thompson, L., Dubow, J. and Rajeshwar, K.: Heterojunction silicon indium tin oxide photo-electrodes-development of stable systems in aqueous-electrolytes and their applicability to solar-energy conversion and storage. J. Am. Chem. Soc. 105, 324 (1983).CrossRefGoogle Scholar
68.Kronik, L., Ashkenasy, N., Leibovitch, M., Fefer, E., Shapira, Y., Gorer, S. and Hodes, G.: Surface states and photovoltaic effects in CdSe quantum dot films. J. Electrochem. Soc. 145, 1748 (1998).CrossRefGoogle Scholar
69.Zaban, A., Meier, A. and Gregg, B.A.: Electric potential distribution and short-range screening in nanoporous TiO2 electrodes. J. Phys. Chem. B 101, 7985 (1997).CrossRefGoogle Scholar
70.Cao, F., Oskam, G. and Searson, P.C.: A solid state dye sensitised photoelectrochemical cell. J. Phys. Chem. 99, 17071 (1995).CrossRefGoogle Scholar
71.Solbrand, A., Lindstrom, H., Rensmo, H., Hagfeldt, A., Lindquist, S.E. and Sodergren, S.: Electron transport in the nanostructured TiO2-electrolyte system studied with time-resolved photocurrents. J. Phys. Chem. B 101, 2514 (1997).CrossRefGoogle Scholar
72.Chamberlain, G.A.: Organic solar-cells—A review. Solar Cells 8, 47 (1983).CrossRefGoogle Scholar
73.Peumans, P., Yakimov, A. and Forrest, S.R.: Small molecular weight organic thin-film photodetectors and solar cells. J. Appl. Phys. 93, 3693 (2003).CrossRefGoogle Scholar
74.Peumans, P., Bulovic, V. and Forrest, S.R.: Efficient photon harvesting at high optical intensities in ultrathin organic double-heterostructure photovoltaic diodes. Appl. Phys. Lett. 76, 2650 (2000).CrossRefGoogle Scholar
75.Yakimov, A. and Forrest, S.R.: High photovoltage multiple-heterojunction organic solar cells incorporating interfacial metallic nanoclusters. Appl. Phys. Lett. 80, 1667 (2002).CrossRefGoogle Scholar
76.Hiramoto, M., Suezaki, M., and Yokoyama, M.: Effect of thin gold interstitial-layer on the photovoltaic properties of tandem organic solar-cell. Chem. Lett., 327 (1990).Google Scholar
77.Peumans, P. and Forrest, S.R.: Very-high-efficiency double-heterostructure copper phthalocyanine/C-60 photovoltaic cells. Appl. Phys. Lett. 79, 126 (2001).CrossRefGoogle Scholar
78.Pacios, R., Nelson, J., Bradley, D.D.C., Virgili, T., Lanzani, G. and Brabec, C.J.: Ultrafast spectroscopic studies in polyfluorene: [6,6]-phenyl C-61-butyric acid methyl ester blend films: monitoring the photoinduced charge transfer process. J. Phys.: Condens. Matter 16, 8105 (2004).Google Scholar
79.Brabec, C.J., Zerza, G., Cerullo, G., De Silvestri, S., Luzzati, S., Hummelen, J.C. and Sariciftci, S.: Tracing photoinduced electron transfer process in conjugated polymer/fullerene bulk heterojunctions in real time. Chem. Phys. Lett. 340, 232 (2001).CrossRefGoogle Scholar
80.Shaheen, S.E., Brabec, C.J., Sariciftci, N.S., Padinger, F., Fromherz, T. and Hummelen, J.C.: 2.5% efficient organic plastic solar cells. Appl. Phys. Lett. 78, 841 (2001).CrossRefGoogle Scholar
81.Kroon, J.M., Wienk, M.M., Verhees, W.J.H. and Hummelen, J.C.: Accurate efficiency determination and stability studies of conjugated polymer/fullerene solar cells. Thin Solid Films 403, 223 (2002).CrossRefGoogle Scholar
82.Munters, T., Martens, T., Goris, L., Vrindts, V., Manca, J., Lutsen, L., De Ceuninck, W., Vanderzande, D., De Schepper, L., Gelan, J., Sariciftci, N.S. and Brabec, C.J.: A comparison between state-of-the-art ‘gilch’ and ‘sulphinyl’ synthesised MDMO-PPV/PCBM bulk hetero-junction solar cells. Thin Solid Films. 403, 247 (2002).CrossRefGoogle Scholar
83.Aernouts, T., Geens, W., Poortmans, J., Heremans, P., Borghs, S. and Mertens, R.: Extraction of bulk and contact components of the series resistance in organic bulk donor-acceptor-heterojunctions. Thin Solid Films 403, 297 (2002).CrossRefGoogle Scholar
84.Janssen, R.A.J., Hummelen, J.C. and Sariciftci, N.S.: Polymer-fullerene bulk heterojunction solar cells. MRS Bull. 30, 33 (2005).CrossRefGoogle Scholar
85.Hoppe, H., Niggemann, M., Winder, C., Kraut, J., Hiesgen, R., Hinsch, A., Meissner, D. and Sariciftci, N.S.: Nanoscale morphology of conjugated polymer/fullerene-based bulk-heterojunction solar cells. Adv. Funct. Mater. 14, 1005 (2004).CrossRefGoogle Scholar
86.Camaioni, N., Catellani, M., Luzzati, S. and Migliori, A.: Morphological characterization of poly(3-octylthiophene):plasticizer: C-60 blends. Thin Solid Films 403, 489 (2002).CrossRefGoogle Scholar
87.Stalmach, U., de Boer, B., Videlot, C., van Hutten, P.F. and Hadziioannou, G.: Semiconducting diblock copolymers synthesized by means of controlled radical polymerization techniques. J. Am. Chem. Soc. 122, 5464 (2000).CrossRefGoogle Scholar
88.Hadziioannou, G.: Semiconducting block copolymers for self-assembled photovoltaic devices. MRS Bull. 27, 456 (2002).CrossRefGoogle Scholar
89.Schmidt-Mende, L., Fechtenkotter, A., Mullen, K., Moons, E., Friend, R.H. and MacKenzie, J.D.: Self-organized discotic liquid crystals for high-efficiency organic photovoltaics. Science 293, 1119 (2001).CrossRefGoogle ScholarPubMed
90.Baur, J.W., Durstock, M.F., Taylor, B.E., Spry, R.J., Reulbach, S. and Chiang, L.Y.: Photovoltaic interface modification via electrostatic self-assembly. Synth. Met. 121, 1547 (2001).CrossRefGoogle Scholar
91.Durstock, M.F., Taylor, B., Spry, R.J., Chiang, L., Reulbach, S., Heitfeld, K. and Baur, J.W.: Electrostatic self-assembly as a means to create organic photovoltaic devices. Synth. Met. 116, 373 (2001).CrossRefGoogle Scholar
92.Schroeder, R., Heflin, J.R., Wang, H., Gibson, H.W. and Graupner, W.: Control of excited state dynamics in ionically self-assembled monolayers of conjugated molecules. Synth. Met. 121, 1521 (2001).CrossRefGoogle Scholar
93.Kietzke, T., Neher, D., Landfester, K., Montenegro, R., Guntner, R. and Scherf, U.: Novel approaches to polymer blends based on polymer nanoparticles. Nat. Mater. 2, 408 (2003).CrossRefGoogle ScholarPubMed
94.Arango, A.C., Carter, S.A. and Brock, P.J.: Charge transfer in photovoltaics consisting of interpenetrating networks of conjugated polymer and TiO2 nanoparticles. Appl. Phys. Lett. 74, 1698 (1999).CrossRefGoogle Scholar
95.Coakley, K.M., Liu, Y., Goh, C. and McGehee, M.D.: Ordered organic-inorganic bulk heterojunction photovoltaic cells. MRS Bull. 30, 37 (2005).CrossRefGoogle Scholar
96.Coakley, K.M. and McGehee, M.D.: Photovoltaic cells made from conjugated polymers infiltrated into mesoporous titania. Appl. Phys. Lett. 83, 3380 (2003).CrossRefGoogle Scholar
97.Ravirajan, P., Haque, S.A., Durrant, J.R., Poplavskyy, D., Bradley, D.D.C. and Nelson, J.: Hybrid nanocrystalline TiO2 solar cells with a fluorene-thiophene copolymer as a sensitizer and hole conductor. J. Appl. Phys. 95, 1473 (2004).CrossRefGoogle Scholar
98.Janssen, R.A.J., Beek, W.J.E. and Wienk, M.M.: Efficient hybrid solar cells from zinc oxide nanoparticles and a conjugated polymer. Adv. Mater. 16, 1009 (2004).Google Scholar
99.Alivisatos, A.P.: Semiconductor clusters, nanocrystals, and quantum dots. Science 271, 933 (1996).CrossRefGoogle Scholar
100.Sun, B.Q., Marx, E. and Greenham, N.C.: Photovoltaic devices using blends of branched CdSe nanoparticles and conjugated polymers. Nano Lett. 3, 961 (2003).CrossRefGoogle Scholar
101.Hoppe, H. and Sariciftci, N.S.: Organic solar cells: An overview. J. Mater. Res. 19, 200 (2004).CrossRefGoogle Scholar
102.Roncali, J.: Synthetic principles for bandgap control in linear pi-conjugated systems. Chem. Rev. 97, 173 (1997).CrossRefGoogle ScholarPubMed
103.McCullough, R.D.: The chemistry of conducting polythiophenes. Adv. Mater. 10, 93 (1998).3.0.CO;2-F>CrossRefGoogle Scholar
104.Durrant, J.R., Haque, S.A. and Palomares, E.: Towards optimization of electron transfer processes in dye sensitized solar cells. Coordin. Chem. Rev. 248, 1247 (2004).CrossRefGoogle Scholar
105.Brabec, C.J., Shaheen, S.E., Winder, C., Sariciftci, N.S. and Denk, P.: Effect of LiF/metal electrodes on the performance of plastic solar cells. Appl. Phys. Lett. 80, 1288 (2002).CrossRefGoogle Scholar
106.Ahn, Y.J., Kang, G.W. and Lee, C.H.: Photovoltaic properties of multilayer heterojunction organic solar cells. Mol. Cryst. Liq. Cryst. 377, 301 (2002).CrossRefGoogle Scholar
107.Ahn, Y.J., Kang, G.W., Lee, C.H., Yeom, I.S. and Jin, S.H.: Photovoltaic properties of polymer-based solar cells. Synth. Met. 137, 1447 (2003).CrossRefGoogle Scholar
108.Frohne, H., Shaheen, S.E., Brabec, C.J., Muller, D.C., Sariciftci, N.S. and Meerholz, K.: Influence of the anodic work function on the performance of organic solar cells. Chem. Phys. Chem. 3, 795 (2002).3.0.CO;2-A>CrossRefGoogle ScholarPubMed
109.Sheats, J.R.: Manufacturing and commercialization issues in organic electronics. J. Mater. Res. 19, 1974 (2004).CrossRefGoogle Scholar
110.Shtein, M., Peumans, P., Benziger, J.B. and Forrest, S.R.: Direct, mask- and solvent-free printing of molecular organic semiconductors. Adv. Mater. 16, 1615 (2004).CrossRefGoogle Scholar
111.Shtein, M., Peumans, P., Benziger, J.B. and Forrest, S.R.: Direct mask-free patterning of molecular organic semiconductors using organic vapor jet printing. J. Appl. Phys. 96, 4500 (2004).CrossRefGoogle Scholar
112.Shtein, M., Peumans, P., Benziger, J.B. and Forrest, S.R.: Micropatterning of small molecular weight organic semiconductor thin films using organic vapor phase deposition. J. Appl. Phys. 93, 4005 (2003).CrossRefGoogle Scholar
113.Yang, X.N., van Duren, J.K.J., Janssen, R.A.J., Michels, M.A.J. and Loos, J.: Morphology and thermal stability of the active layer in poly(p-phenylenevinylene)/methanofullerene plastic photovoltaic devices. Macromolecules 37, 2151 (2004).CrossRefGoogle Scholar
114.Muller, C.D., Falcou, A., Reckefuss, N., Rojahn, M., Wiederhirn, V., Rudati, P., Frohne, H., Nuyken, O., Becker, H. and Meerholz, K.: Multi-colour organic light-emitting displays by solution processing. Nature 421, 829 (2003).CrossRefGoogle ScholarPubMed