Solar cells from colloidal nanocrystals: Fundamentals, materials, devices, and economics

Current Opinion in Colloid and Interface Science

Volumn 14, Issue 4, 2009, Pages 245-259

  Hillhouse, Hugh W ^a,b   Beard, Matthew C ^b  

^a PURDUE UNIVERSITY   (United States)

^b NATIONAL RENEWABLE ENERGY LABORATORY   (United States)

Author keywords

Carrier multiplication; CuInSe2; Economics; Energy; Grand challenge; MEG; Multiple exciton generation; Nanocrystal; Nanostructured; PbS; PbSe; Photovoltaic; Quantum dot; Schottky barrier; Shockley Queisser; Sintered; Solar

Indexed keywords

CARRIER MULTIPLICATION; CUINSE2; ENERGY; GRAND CHALLENGE; MEG; MULTIPLE EXCITON GENERATION; NANOSTRUCTURED; PBS; PBSE; PHOTOVOLTAIC; QUANTUM DOT; SCHOTTKY BARRIER; SHOCKLEY-QUEISSER; SINTERED; SOLAR;

CELL MEMBRANES; CONVERSION EFFICIENCY; COSTS; ENERGY GAP; EXCITONS; INDIUM ARSENIDE; LASER PULSES; NANOCRYSTALS; OPTICAL WAVEGUIDES; PHOTOVOLTAIC CELLS; QUANTUM OPTICS; SCHOTTKY BARRIER DIODES; SEMICONDUCTOR QUANTUM DOTS; SINTERING; SOLAR CELLS; SOLAR POWER GENERATION; VACUUM DEPOSITION;

SOLAR ENERGY;

ARSENIC; NANOCRYSTAL; QUANTUM DOT; SILICON;

COLLOID; ELECTRIC POTENTIAL; ELECTRON; PHYSICS; REVIEW; SEMICONDUCTOR; SOLAR ENERGY; SPECTRAL SENSITIVITY; VACUUM;

EID: 67649413034     PISSN: 13590294     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.cocis.2009.05.002     Document Type: Review

References (107)

1. O Rouke S., Kim P., and Polavarapu H. Solar Photovoltaic Industry: Looking through the Storm (2009), Deutsche Bank. Details the current status of the industry including manufacturing costs, average selling prices, profit margins, and projections.
2. Solarbuzz.com: Solar Electricity Price Index. http://www.solarbuzz.com/SolarPrices.htm. This site is an excellent resource that provides monthly updates to the price of solar electricity, modules, battery storage, and inverters.
3. U.S. Department of Energy, Energy Information Administration: Average Retail Price of Electricity to Ultimate Customers by End-Use Sector and by State. http://www.eia.doe.gov/cneaf/electricity/epm/table5_6_b.html.
4. First Solar: 2008 Annual Report. http://investor.firstsolar.com/.
5. Ginley D., Green M.A., and Collins R. Solar energy conversion toward 1 TW. MRS Bull 33 (2008) 355-364
6. Fthenakis V., Mason J.E., and Zweibel K. The technical, geograhical, and economic feasibility for solar energy to supply the energy needs of the U.S. Energy Policy 37 (2009) 387-399
7. Shockley W., and Queisser H.J. Detailed balance limit of efficiency of p-n junction solar cells. J Appl Physi 32 (1961) 510
8. Wurfel P. The chemical potential of radiation. J Phys C Solid State Phys 15 (1982) 3967-3985
9. Ries H., and McEvoy A.J. Chemical potential and temperature of light. J Photochem Photobiol A Chem 59 (1991) 11-18. Nicely illustrates the connection between chemical potential and any photochemical, photoelectrochemical, and photovoltaic devices.
10. Ross R.T., and Nozik A.J. Efficiency of hot-carrier solar-energy converters. J Appl Physi 53 (1982) 3813-3818. Calculated the power conversion efficiency for the case where photogenerated carriers do not lose excess energy from intraband cooling down to the semiconductor band edge.
11. Schaller R.D., and Klimov V.I. High efficiency carrier multiplication in PbSe nanocrystals: Implications for solar energy conversion. Phys Rev Lett (2004) 92. Measured for the first time MEG in PbSe NCs using the dynamics signature of multiexciton decay in transient bleaching measurements. Showed that MEG turns on very strongly for photon energies that are at least 3 times the NC effective bandgap.
12. Ellingson R.J., Beard M.C., Johnson J.C., Yu P.R., Micic O.I., Nozik A.J., et al. Highly efficient multiple exciton generation in colloidal PbSe and PbS quantum dots. Nano Lett 5 (2005) 865-871. Measured MEG efficiency for PbSe and PbS NCs using two techniques, (transient bleaching and photoinduced absorption) and showed that the two techniques give indentical MEG results. Proposed a coherent superpostion of single and multi-exciton states that are coupled through the Coulomb interaction to explain enhanced MEG in NCs.
13. Nozik A.J. Multiple exciton generation in semiconductor quantum dots. Chem Phys Lett 457 (2008) 3-11. Recent review of multiple exciton generation in semiconductor nanocrystals.
14. Hanna M.C., and Nozik A.J. Solar conversion efficiency of photovoltaic and photoelectrolysis cells with carrier multiplication absorbers. J Appl Physi 100 (2006) 074510. Thermodynamic analysis of ideal efficiency for solar energy conversion strategies that incorporate MEG.
15. Beard M.C., and Ellingson R.J. Multiple exciton generation in semiconductor nanocrystals: Toward efficient solar energy conversion. Laser Photonics Rev 2 (2008) 377-399
16. McGuire J.A., Joo J., Pietryga J.M., Schaller R.D., and Klimov V.I. New aspects of carrier multiplication in semiconductor nanocrystals. Acc Chem Res 41 (2008) 1810-1819. Review of MEG in nanocrystals and discussion of charging in NCs as a source of the variability in reported MEG efficiencies.
17. Snaith H.J., and Schmidt-Mende L. Advances in liquid-electrolyte and solid-state dye-sensitized solar cells. Adv Mater 19 (2007) 3187-3200
18. Murray C.B., Norris D.J., and Bawendi M.G. Synthesis and characterization of nearly monodisperse CdE (E = S, SE, TE) semiconductor nanocrystallites. J Am Chem Soc 115 (1993) 8706-8715. Seminal paper that demonstrated the synthesis of monodisperse cadmium chalcogenide quantum dots. However, the synthesis used highly reactive reagents.
19. Peng Z.A., and Peng X.G. Formation of high-quality CdTe, CdSe, and CdS nanocrystals using CdO as precursor. J Am Chem Soc 123 (2001) 183-184. Demonstrated the use of CdO to synthesize high quality monodisperse quantum dots. This method made the synthesis of cadmium chacogenides much easier and safer.
20. Xie R.G., and Peng X.G. Synthetic scheme for high-quality InAs nanocrystals based on self-focusing and one-pot synthesis of InAs-based core-shell nanocrystals. Angew Chem Int Ed 47 (2008) 7677-7680
21. Kudera S., Carbone L., Manna L., and Parak W.J. Growth mechanism, shape, and composition control of semiconductor nanocrystals. In: Rogach A.L. (Ed). Semiconductor Nanocrystal Quantum Dots: Synthesis Assembly, Spectroscopy, and Applications (2008), Springer-Verlag 1-34
22. Reiss P. Synthesis of semiconductor nanocrystals in organic solvents. In: Rogach A.L. (Ed). Semiconductor Nanocrystal Quantum Dots: Synthesis Assembly, Spectroscopy, and Applications (2008), Springer-Verlag 35-72. Nice recent review of colloidal nanocrystal syntheses.
23. Guo Q., Kim S.J., Kar M., Shafarman W.N., Birkmire R.W., Stach E.A., et al. Development of CuInSe2 nanocrystal and nanoring inks for low-cost solar cells. Nano Lett 8 (2008) 2982-2987. Reported the first synthesis of stoichiometric chalcopyrite structured CuInSe2 nanocrystals in the peer-reviewed literature. Also demonstrated the formation of ∼ 3% efficiency solar cells by sintering the CuInSe2 nanocrystal ink.
24. Wu Y., Wadia C., Ma W.L., Sadtler B., and Alivisatos A.P. Synthesis and photovoltaic application of copper(I) sulfide nanocrystals. Nano Lett 8 (2008) 2551-2555. Reported the synthesis of Cu2S nanocrystals and their use to make solar cells on flexible substrates.
25. Mangolini L., Thimsen E., and Kortshagen U. High-yield plasma synthesis of luminescent silicon nanocrystals. Nano Lett 5 (2005) 655-659
26. Wadia C., Alivisatos A.P., and Kammen D.M. Materials availability expands the opportunity for large-scale photovoltaics deployment. Environ Sci Technol 43 (2009) 2072-2077. Detailed study of photovoltaic material abundance, cost, and theoretical efficiency. These parameters are combined to form a list of prospective material systems for the development of future solar cells.
27. Murray C.B., Kagan C.R., and Bawendi M.G. Synthesis and characterization of monodisperse nanocrystals and close-packed nanocrystal assemblies. Annu Rev Mater Sci 30 (2000) 545-610
28. Murray C.B., Sun S.H., Gaschler W., Doyle H., Betley T.A., and Kagan C.R. Colloidal synthesis of nanocrystals and nanocrystal superlattices. IBM J Res Develop 45 (2001) 47-56
29. Micic O.I., Ahrenkiel S.P., and Nozik A.J. Synthesis of extremely small InP quantum dots and electronic coupling in their disordered solid films. Appl Phys Lett 78 (2001) 4022-4024
30. Wang C.J., Shim M., and Guyot-Sionnest P. Electrochromic semiconductor nanocrystal films. Appl Phys Lett 80 (2002) 4-6
31. Efros A.L., Kharchenko V.A., and Rosen M. Breaking the phonon bottleneck in nanometer quantum dots: role of Auger-like processes. Solid State Commun 93 (1995) 281. Theoretical description of Auger-cooling in semiconductor nanocrystals.
32. Guyot-Sionnest P., Shim M., Matranga C., and Hines M. Intraband relaxation in CdSe quantum dots. Phys Rev B 60 (1999) R2181-R2184
33. Klimov V.I., Mikhailovsky A.A., McBranch D.W., Leatherdale C.A., and Bawendi M.G. Quantization of multiparticle auger rates in semiconductor quantum dots. Science 287 (2000) 1011-1013. Measured Auger recombination dynamics in semiconductor nanocrystals using transient absorption spectroscopy. Found that AR is quantized in nanocrystals.
34. Blackburn J.L., Ellingson R.J., Micic O.I., and Nozik A.J. Electron relaxation in colloidal InP quantum dots with photo-generated excitons or chemically injected electrons. J Phys Chem B 107 (2003) 102-109
35. Guyot-Sionnest P., Wehrenberg B., and Yu D. Intraband relaxation in CdSe nanocrystals and the strong influence of the surface ligands. J Chem Phys 123 (2005) 074709
36. Kortan A.R., Hull R., Opila R.L., Bawendi M.G., Steigerwald M.L., Carroll P.J., et al. Nucleation and growth of cadmium selendie on zinc sulfide quantum crystallite seeds, and vice versa, in inverse micelle media. J Am Chem Soc 112 (1990) 1327
37. Hines M.A., and Guyot-Sionnest P. Synthesis and characterization of strongly luminescent ZnS-capped CdSe nanocrystals. J Phys Chem B 100 (1996) 468
38. Efros AL. Auger Processes in Nanosize Semiconductor Crystals. In Semiconductor Nanocrystals. Edited by Efros, A.L., Lockwood, D.J., Tsybeskov, L.: Kluwer Academic / Plenum Publishers; 2003:52-72. [Lockwood DJ (Series Editor): Nanostructure Science and Technology, vol 6].
39. Efros A.L., and Rosen M. Random telegraph signal in the photoluminescence intensity of a single quantum dot. Phys Rev Lett 78 (1997) 1110-1113
40. Nozik A.J. Quantum dot solar cells. Phys E Low-Dimens Syst Nanostruct 14 (2002) 115-120. Three basic designs for incorporating NCs within solar cells are proposed: (1) metal-oxide NC sensitized nanoporous films, (2) NC-polymer hybrids, and (3) NC films that have strong inter-NC coupling. Based on the enhancement of Auger processes, multiple exciton generation within NCs is predicted to be enhanced over impact ionization in bulk materials.
41. Pandey A., and Guyot-Sionnest P. Slow electron cooling in colloidal quantum dots. Science 322 (2008) 929-932. Demonstrated a phonon bottleneck effect in carefully constructed core/shell/shell nanocrystals. Showed that by understanding the relaxation mechanism the rates can be controlled.
42. Gregg B.A. Excitonic solar cells. J Phys Chem B 107 (2003) 4688-4698. Presents a unified formalism for photovoltaic devices that encompasses both excitonic solar cells and conventional solar cells, illustrating their similarities and differences.
43. Parsons C.A., Peterson M.W., Thacker B.R., Turner J.A., and Nozik A.J. Single quantum well electrodes for photoelectrochemistry. J Phys Chem 94 (1990) 3381
44. Nozik A.J., Turner J.A., and Peterson M.W. Kinetics of electron transfer from photoexcited superlattice electrodes. J Phys Chem 92 (1988) 2493
45. Smith B.B., and Nozik A.J. Theoretical studies of electronic state localization and wormholes in silicon quantum dot arrays. Nano Lett 1 (2001) 36
46. Yu D., Wang C.J., and Guyot-Sionnest P. n-type conducting CdSe nanocrystal solids. Science 300 (2003) 1277-1280. First report of producing n-type NC films, which was achieved by treating the film with potassium. The conductivity of the film increased by 12 orders of magnitude.
47. Talapin D.V., and Murray C.B. PbSe nanocrystal solids for n- and p-channel thin film field-effect transistors. Science 310 (2005) 86-89. Showed that treating PbSe NC films with hydrazine produced n-type FETs with high carrier mobilities. The n-type films could be reversible switched to p-type.
48. Law M., Luther J.M., Song O., Hughes B.K., Perkins C.L., and Nozik A.J. Structural, optical, and electrical properties of PbSe nanocrystal solids treated thermally or with simple amines. J Am Chem Soc 130 (2008) 5974-5985. Studied structural and electrical properties of PbSe films that were annealed or chemically treated with simple amines.
49. Luther J.M., Law M., Beard M.C., Song Q., Reese M.O., Ellingson R.J., et al. Schottky solar cells based on colloidal nanocrystal films. Nano Lett 8 (2008) 3488-3492. Describes a Schottky-junction solar cell where PbSe NC films are the active element. Demonstrated ∼ 2.1% conversion efficiency and exceptionally high photocurrents.
50. Norris D.J., Efros A.L., and Erwin S.C. Doped nanocrystals. Science 319 (2008) 1776-1779. Describes doping with intentional impurities within NCs. Very nice overview of the challenges and status of doping semiconductor NCs.
51. Lee J.S., Shevchenko E.V., and Talapin D.V. Au-PbS core-shell nanocrystals: plasmonic absorption enhancement and electrical doping via intra-particle charge transfer. J Am Chem Soc 130 (2008) 9673
52. Urban J.J., Talapin D.V., Shevchenko E.V., Kagan C.R., and Murray C.B. Synergismin binary nanocrystal superlattices leads to enhanced p-type conductivity in self-assembled PbTe/Ag-2 Te thin films. Nat Mater 6 (2007) 115-121
53. Romero H.E., and Drndic M. Coulomb blockade and hopping conduction in PbSe quantum dots. Phys Rev Lett 95 (2005) 4
54. Drndic M., Jarosz M.V., Morgan N.Y., Kastner M.A., and Bawendi M.G. Transport properties of annealed CdSe colloidal nanocrystal solids. J Appl Physi 92 (2002) 7498-7503
55. Mentzel T.S., Porter V.J., Geyer S., MacLean K., Bawendi M.G., and Kastner M.A. Charge transport in PbSe nanocrystal arrays. Phys Rev B 77 (2008) 8
56. Jarosz M.V., Porter V.J., Fisher B.R., Kastner M.A., and Bawendi M.G. Photoconductivity studies of treated CdSe quantum dot films exhibiting increased exciton ionization efficiency. Phys Rev B (2004) 70
57. Jarosz M.V., Stott N.E., Drndic M., Morgan N.Y., Kastner M.A., and Bawendi M.G. Observation of bimolecular carrier recombination dynamics in close-packed films of colloidal CdSe nanocrystals. J Phys Chem B 107 (2003) 12585-12588
58. Leatherdale C.A., Kagan C.R., Morgan N.Y., Empedocles S.A., Kastner M.A., and Bawendi M.G. Photoconductivity in CdSe quantum dot solids. Phys Rev B 62 (2000) 2669
59. Guyot-Sionnest P., and Wang C. Fast voltammetric and electrochromic response of semiconductor nanocrystal thin films. J Phys Chem B 107 (2003) 7355-7359
60. Shim M., and Guyot-Sionnest P. n-type colloidal semiconductor nanocrystals. Nature 407 (2000) 981
61. Wang C.J., Shim M., and Guyot-Sionnest P. Electrochromic nanocrystal quantum dots. Science 291 (2001) 2390-2392
62. Wang F., Dukovic G., Brus L.E., and Heinz T.F. Time-resolved fluorescence of carbon nanotubes and its implication for radiative lifetimes. Phys Rev Lett 92 (2004) 177401
63. Wehrenberg B.L., and Guyot-Sionnest P. Electron and hole injection in PbSe quantum dot films. J Am Chem Soc 125 (2003) 7806-7807
64. Wehrenberg B.L., Yu D., Ma J.S., and Guyot-Sionnest P. Conduction in charged PbSe nanocrystal films. J Phys Chem B 109 (2005) 20192-20199
65. Yu P., Nedeljkovic J.M., Ahrenkiel P.A., Ellingson R.J., and Nozik A.J. Size dependent femtosecond electron cooling dynamics in CdSe quantum rods. Nano Lett 4 (2004) 1089
66. Beard M.C., Turner G.M., Murphy J.E., Micic O.I., Hanna M.C., Nozik A.J., et al. Electronic coupling in InP nanoparticle arrays. Nano Lett 3 (2003) 1695
67. Remacle F. On electronic properties of assemblies of quantum nanodots. J Phys Chem A (2000) 4739-4747
68. Franceschetti A., and Zunger A. Exciton dissociation and interdot transport in CdSe quantum-dot molecules. Phys Rev B 63 (2001) 4
69. Luther J.M., Law M., Song Q., Perkins C.L., Beard M.C., and Nozik A.J. Structural, optical and electrical properties of self-assembled films of PbSe nanocrystals treated with 1,2-ethanedithiol. ACS Nano 2 (2008) 271-280. Introduced a layer-by-layer procedure for producing uniform NC films using 1,2-ethanedithiol to remove oleic acid capping ligands and more strongly couple the NCs.
70. Arango A.C., Oertel D.C., Xu Y.F., Bawendi M.G., and Bulovic V. Heterojunction photovoltaics using printed colloidal quantum dots as a photosensitive layer. Nano Lett 9 (2009) 860-863. Demonstrated a solar cell utilizing CdSe semiconductor nanocrystals as the active element with a high Voc.
71. Ma W., Luther J.M., Zheng H.M., Wu Y., and Alivisatos A.P. Photovoltaic devices employing ternary PbSxSe1-x nanocrystals. Nano Lett 9 (2009) 1699-1703
72. Johnston K.W., Pattantyus-Abraham A.G., Clifford J.P., Myrskog S.H., Hoogland S., Shukla H., et al. Efficient Schottky-quantum-dot photovoltaics: the roles of depletion, drift, and diffusion. Appl Phys Lett 92 (2008) 122111
73. Johnston K.W., Pattantyus-Abraham A.G., Clifford J.P., Myrskog S.H., MacNeil D.D., Levina L., et al. Schottky-quantum dot photovoltaics for efficient infrared power conversion. Appl Phys Lett 92 (2008) 151115
74. Klem E.J.D., MacNeil D.D., Levina L., and Sargent E.H. Solution processed photovoltaic devices with 2% infrared monochromatic power conversion efficiency: performance optimization and oxide formation. Adv Mater 20 (2008) 3433
75. Beard M.C., Midgett A.G., Law M., Semonin O.E., Ellingson R.J., and Nozik A.J. Variations in the quantum efficiency of multiple exciton generation for a series of chemically treated PbSe nanocrystal films. Nano Lett 9 (2009) 836-845. Measured MEG efficiency in a series of chemically treated NC films and demonstrated that the surface ligand can increase or decrease MEG.
76. Law M., Beard M.C., Choi S., Luther J.M., Hanna M., and Nozik A.J. Determining the internal quantum efficiency of PbSe nanocrystal solar cells with the aid of an optical model. Nano Lett 8 (2008) 3904-3910
77. Sun B., Findikoglu A.T., Sykora M., Werder D.J., and Klimov V.I. Hybrid photovoltaics based on semiconductor nanocrystals and amorphous silicon. Nano Lett 9 (2009) 1235-1241. Presents a hybrid NC solar cell and demonstrates that quantum confinement is preserved in the NCs.
78. Kirchartz T., and Rau U. Modeling charge carrier collection in multiple exciton generating PbSe quantum dots. Thin Solid Films 517 (2009) 2438-2442. Extended the detailed-balance modeling approach to included the effects of non-ideal extraction and finite mobilities and examined the case for MEG solar cells. Model can be used to determine critical values of mobility and extraction times.
79. Jha P.P., and Guyot-Sionnest P. Trion decay in colloidal quantum dots. ACS Nano 3 (2009) 1011-1015
80. Ben-Lulu M., Mocatta D., Bonn M., Banin U., and Ruhman S. On the absence of detectable carrier multiplication in a transient absorption study of InAs/CdSe/ZnSe core/shell1/shell2 quantum dots. Nano Lett 8 (2008) 1207-1211
81. Pijpers J.J.H., Hendry E., Milder M.T.W., Fanciulli R., Savolainen J., Herek J.L., Vanmaekelbergh D., Ruhman S., Mocatta D., Oron D., et al. Carrier multiplication and its reduction by photodoping in colloidal InAs quantum dots. J Phys Chem C 111 (2007) 4146-4152
82. Schaller R.D., Pietryga J.M., and Klimov V.I. Carrier multiplication in InAs nanocrystal quantum dots with an onset defined by the energy conservation limit. Nano Lett 7 (2007) 3469-3476
83. Nair G., and Bawendi M.G. Carrier multiplication yields of CdSe and CdTe nanocrystals by transient photoluminescence spectroscopy. Phys Rev B 76 (2007) 081304
84. Schaller R.D., Sykora M., Jeong S., and Klimov V.I. High-efficiency carrier multiplication and ultrafast charge separation in semiconductor nanocrystals studied via time-resolved photoluminescence. J Phys Chem B 110 (2006) 25332-25338
85. Nair G., Geyer S.M., Chang L.Y., and Bawendi M.G. Carrier multiplication yields in PbS and PbSe nanocrystals measured by transient photoluminescence. Phys Rev B 78 (2008) 125325. Measured MEG yields in PbSe and PbS NCs and questions whether MEG is enhanced in NCs over impact ionization in bulk materials.
86. Trinh M.T., Houtepen A.J., Schins J.M., Hanrath T., Piris J., Knulst W., et al. In spite of recent doubts carrier multiplication does occur in PbSe nanocrystals. Nano Lett 8 (2008) 1713-1718
87. Ji M., Park S., Conner S.T., Mokari T., Cui Y., and Gaffney K.J. Efficient mulitple exciton generation observed in colloidal PbSe quantum dots with temporally and spectrally resolved intraband excitation. Nano Lett 9 (2009) 1217-1222
88. Nozik A.J. Spectroscopy and hot electron relaxation dynamics in semiconductor quantum wells and quantum dots. Annu Rev Phys Chem 52 (2001) 193-231. Review of hot electron spectroscopy in quantum structures.
89. Klimov V.I., Mikhailovsky A.A., McBranch D.W., Leatherdale C.A., and Bawendi M.G. Mechanisms for intraband energy relaxation in semiconductor quantum dots: the role of electron-hole interactions. Phys Rev B 61 (2000) R13349-R13352
90. Harbold J.M., Du H., Krauss T.D., Cho K.S., Murray C.B., and Wise F.W. Time-resolved intraband relaxation of strongly confined electrons and holes in colloidal PbSe nanocrystals. Phys Rev B 72 (2005) 195312
91. Kilina S.V., Craig C.F., Kilin D.S., and Prezhdo O.V. Ab initio time-domain study of phonon-assisted relaxation of charge carriers in a PbSe quantum dot. J Phys Chem C 111 (2007) 4871-4878
92. Huynh W.U., Dittmer J.J., and Alivisatos A.P. Hybrid nanorod-polymer solar cells. Science 295 (2002) 2425-2427. Demonstrated a solution phase route to a hybrid CdSe nanocrystal-polymer solar cell. While the device (and all like it) are still less efficient that all-polymer based solar cells, it demonstrated an important fabrication concept.
93. Gur I., Fromer N.A., Chen C.P., Kanaras A.G., and Alivisatos A.P. Hybrid solar cells with prescribed nanoscale morphologies based on hyperbranched semiconductor nanocrystals. Nano Lett 7 (2007) 409-414
94. Wang D., Kopidakis N., Reese M.O., and Gregg B.A. Treating poly(3-hexylthiophene) with dimethylsulfate improves its photoelectrical properties. Chem Mater 20 (2008) 6307-6309
95. Gur I., Fromer N.A., Geier M.L., and Alivisatos A.P. Air-stable all-inorganic nanocrystal solar cells processed from solution. Science 310 (2005) 462-465. Showed an all inorganic solar cell that was spin-cast from nanocrystal solutions. The devices are air-stable and approach 3% efficiency.
96. Anderson I.E., Breeze A.J., Olson J.D., Yang L., Sahoo Y., and Carter S.A. All-inorganic spin-cast nanoparticle solar cells with nonselective electrodes. Appl Phys Lett 94 (2009) 3
97. Basol B.M. Low cost techniques for the preparation of Cu(In,Ga)(Se,S)(2) absorber layers. Thin Solid Films 361 (2000) 514-519
98. Eberspacher C., Fredric C., Pauls K., and Serra J. Thin-film CIS alloy PV materials fabricated using non-vacuum, particles-based techniques. Thin Solid Films 387 (2000) 18-22. This paper showed that particulate precursors of could be deposited by non-vacuum techniques and that they could be sintered and converted to Cu-In-Se2 to yield cells with efficiency up to 11.7%. There are issues with homogeneity and delamination that have prevented commercialization, but nevertheless, this important paper showed the potential that is possible by such non-vacuum particulate methods.
99. Kaelin M., Rudmann D., and Tiwari A.N. Low cost processing of CIGS thin film solar cells. Solar Energy 77 (2004) 749-756
100. Norsworthy G., Leidholm C.R., Halani A., Kapur V.K., Roe R., Basol B.M., et al. CIS film growth by metallic ink coating and selenization. Sol Energy Mater Sol Cells 60 (2000) 127-134
101. Schulz D.L., Curtis C.J., Flitton R.A., Wiesner H., Keane J., Matson R.J., et al. Cu-In-Ga-Se nanoparticle colloids as spray deposition precursors for Cu(In,Ga)Se-2 solar cell materials. J Electron Mater 27 (1998) 433-437
102. Guo QJ, Agrawal R, Hillhouse HW. Rapid Synthesis of Ternary, Binary, and Multinary Chalcogenide Nanoparticles. US Patent Application, US2007/069349. First synthesis of stoichiometric chalcopyrite CuInSe2, GuGaSe2, and Cu(In,Ga)Se2 nanocrystals. A scalable gradual-heating method is used in a single oleylamine solvent without additional ligands or surfactants. The patent application was filed on May 12, 2007 and includes PXRD, TEM, FESEM and compositional analysis data showing proof of the ternary and quaternary nanocrystal syntheses. All information was contained in a previously filed provisional patent application (60/801,963) which was filed on May 19, 2006. The CuInSe2 syntheses and resulting solar cells were later published in Nano Letters on August 2, 2008 [reference 23 of this review].
103. Panthani M.G., Akhavan V., Goodfellow B., Schmidtke J.P., Dunn L., Dodabalapur A., et al. Synthesis of CuInS2, CuInSe2, and Cu(InxGa1-x)Se2 (CIGS) nanocrystal "inks" for printable photovoltaics. J Am Chem Soc 130 (2008) 16770-16777 [This article was published on November 17, 2008]
104. Tang J., Hinds S., Kelley S.O., and Sargent E.H. Synthesis of colloidal CuGaSe2, CuInSe2, and Cu(InGa)Se2 nanoparticles. Chem Mater 20 (2008) 6906-6910 [This article was published on October 28, 2008]
105. van Duren J.K.J., Leidholm C., Pudov A., Robinson M.R., and Roussillon Y. The next generation of thin-film photovoltaics. In: Gessert T., Durose K., Heske C., Marsillac S., and Wada T. (Eds). Symposium on Thin-Film Compound Semiconductor Photovoltaics held at the 2007 MRS Spring Meeting Apr 09-13; San Francisco, CA (2007) 259-268. First literature report from Nanosolar. Full details of cell fabrication are not reported, but a power-conversion efficiency of 13.95% is shown.
106. Sager BM, Yu D, Robinson MR. Coated nanoparticles and quantum dots for solution-based fabrication of photovoltaic solar cells. US Patent 2007, 7,306,823 B2.
107. Cichos F., von Borczyskowski C., and Orrit M. Power-law intermittency of single emitters. Curr Opin Colloid Interface Sci 12 (2007) 272-284