Abstract

Transparent conductive oxides (TCOs) play a crucial role in solar cells by efficiently transmitting sunlight and extracting photo-generated charge. Here, we show how nanophotonics concepts can be used to transform TCO films into effective photon management layers for solar cells. This is accomplished by patterning the TCO layer present on virtually every thin-film solar cell into an array of subwavelength beams that support optical (Mie) resonances. These resonances can be exploited to concentrate randomly polarized sunlight or to effectively couple it to guided and diffracted modes. We first demonstrate these concepts with a model system consisting of a patterned TCO layer on a thin silicon (Si) film and outline a design methodology for high-performance, TCO-based light trapping coatings. We then show that the short circuit current density from a 300 nm thick amorphous silicon (a-Si) cell with an optimized TCO anti-reflection coating can be enhanced from 19.9 mA/cm2 to 21.1 mA/cm2, out of a possible 26.0 mA/cm2, by using an optimized nanobeam array. The key differences and advantages over plasmonic light trapping layers will be discussed.

© 2012 OSA

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    [CrossRef]

2011

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

J. Grandidier, D. M. Callahan, J. N. Munday, and H. A. Atwater, “Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric nanospheres,” Adv. Mater.23, 1272–1276 (2011).
[CrossRef] [PubMed]

A. Raman, Z. Yu, and S. Fan, “Dielectric nanostructures for broadband light trapping in organic solar cells,” Opt. Express19, 19015–19026 (2011).
[CrossRef] [PubMed]

2010

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

Z. Yu, A. Raman, and S. Fan, “Fundamental limit of nanophotonic light trapping in solar cells,” Proc. Natl. Acad. Sci. USA107, 17491–17496 (2010).
[CrossRef] [PubMed]

H. A. Atwater and A. Polman, “Plasmonics for improved photovoltaic devices,” Nat. Mater.9, 205–213 (2010).
[CrossRef] [PubMed]

2009

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

J. A. Schuller, T. Taubner, and M. L. Brongersma, “Optical antenna thermal emitters,” Nat. Photonics3, 658–661 (2009).
[CrossRef]

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

S. Mokkapati, F. J. Beck, A. Polman, and K. R. Catchpole, “Designing periodic arrays of metal nanoparticles for light-trapping applications in solar cells,” Appl. Phys. Lett.95, 053115 (2009).
[CrossRef]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

2008

J. Y. Lee, S. T. Connor, Y. Cui, and P. Peumans, “Solution-processed metal nanowire mesh transparent electrodes,” Nano Lett.8, 689–692 (2008).
[CrossRef] [PubMed]

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

2006

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

2004

J. Muller, B. Rech, J. Springer, and M. Vanecek, “TCO and light trapping in silicon thin film solar cells,” Sol. Energy77, 917–930 (2004).
[CrossRef]

2001

1999

X. W. Sun and H. S. Kwok, “Optical properties of epitaxially grown zinc oxide films on sapphire by pulsed laser deposition,” J. Appl. Phys.86, 408–411 (1999).
[CrossRef]

Algra, R. E.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Atwater, H. A.

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

J. Grandidier, D. M. Callahan, J. N. Munday, and H. A. Atwater, “Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric nanospheres,” Adv. Mater.23, 1272–1276 (2011).
[CrossRef] [PubMed]

H. A. Atwater and A. Polman, “Plasmonics for improved photovoltaic devices,” Nat. Mater.9, 205–213 (2010).
[CrossRef] [PubMed]

Bakkers, E.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Ballif, C.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Barnard, E.

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

Barnard, E. S.

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

Battaglia, C.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Beck, F. J.

S. Mokkapati, F. J. Beck, A. Polman, and K. R. Catchpole, “Designing periodic arrays of metal nanoparticles for light-trapping applications in solar cells,” Appl. Phys. Lett.95, 053115 (2009).
[CrossRef]

Beckers, T.

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

Bittkau, K.

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

Bohren, C. F.

C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley-VCH, New York, 2010).

Brongersma, M. L.

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

J. A. Schuller, T. Taubner, and M. L. Brongersma, “Optical antenna thermal emitters,” Nat. Photonics3, 658–661 (2009).
[CrossRef]

Brown, A. M.

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

Cai, W.

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

Callahan, D. M.

J. Grandidier, D. M. Callahan, J. N. Munday, and H. A. Atwater, “Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric nanospheres,” Adv. Mater.23, 1272–1276 (2011).
[CrossRef] [PubMed]

Cao, L.

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

Carius, R.

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

Catchpole, K. R.

S. Mokkapati, F. J. Beck, A. Polman, and K. R. Catchpole, “Designing periodic arrays of metal nanoparticles for light-trapping applications in solar cells,” Appl. Phys. Lett.95, 053115 (2009).
[CrossRef]

Chang, R. K.

Charriere, M.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Clemens, B.

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

Clemens, B. M.

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

Connor, S. T.

J. Y. Lee, S. T. Connor, Y. Cui, and P. Peumans, “Solution-processed metal nanowire mesh transparent electrodes,” Nano Lett.8, 689–692 (2008).
[CrossRef] [PubMed]

Courvoisier, F.

Cui, Y.

J. Y. Lee, S. T. Connor, Y. Cui, and P. Peumans, “Solution-processed metal nanowire mesh transparent electrodes,” Nano Lett.8, 689–692 (2008).
[CrossRef] [PubMed]

Despeisse, M.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Diedenhofen, S. L.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Donovan, M.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Escarre, J.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Fahr, S.

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Fan, P.

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

Fan, S.

A. Raman, Z. Yu, and S. Fan, “Dielectric nanostructures for broadband light trapping in organic solar cells,” Opt. Express19, 19015–19026 (2011).
[CrossRef] [PubMed]

Z. Yu, A. Raman, and S. Fan, “Fundamental limit of nanophotonic light trapping in solar cells,” Proc. Natl. Acad. Sci. USA107, 17491–17496 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

Ferry, V. E.

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

Gong, J.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Goodman, J. W.

J. W. Goodman, Introduction to Fourier Optics (Roberts & Co., Colorado, 2005).

Goris, L.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Grandidier, J.

J. Grandidier, D. M. Callahan, J. N. Munday, and H. A. Atwater, “Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric nanospheres,” Adv. Mater.23, 1272–1276 (2011).
[CrossRef] [PubMed]

Haug, F.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Haus, H. A.

H. A. Haus, Waves and Fields in Optoelectronics (Prentice-Hall, New Jersey, 1984).

Hecht, E.

E. Hecht, Optics (Addison-Wesley, Massachusetts, 2002).

Helgert, C.

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Huang, R. F.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Huffman, D. R.

C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley-VCH, New York, 2010).

Jokisaari, J.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Kaas, B. C.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Kroll, M.

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Kusinski, G.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Kwok, H. S.

X. W. Sun and H. S. Kwok, “Optical properties of epitaxially grown zinc oxide films on sapphire by pulsed laser deposition,” J. Appl. Phys.86, 408–411 (1999).
[CrossRef]

Lagendijk, A.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Lederer, F.

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Lee, J. Y.

J. Y. Lee, S. T. Connor, Y. Cui, and P. Peumans, “Solution-processed metal nanowire mesh transparent electrodes,” Nano Lett.8, 689–692 (2008).
[CrossRef] [PubMed]

Liu, J.

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

Mokkapati, S.

S. Mokkapati, F. J. Beck, A. Polman, and K. R. Catchpole, “Designing periodic arrays of metal nanoparticles for light-trapping applications in solar cells,” Appl. Phys. Lett.95, 053115 (2009).
[CrossRef]

Muller, J.

J. Muller, B. Rech, J. Springer, and M. Vanecek, “TCO and light trapping in silicon thin film solar cells,” Sol. Energy77, 917–930 (2004).
[CrossRef]

Munday, J. N.

J. Grandidier, D. M. Callahan, J. N. Munday, and H. A. Atwater, “Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric nanospheres,” Adv. Mater.23, 1272–1276 (2011).
[CrossRef] [PubMed]

Muskens, O. L.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Noriega, R.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Pala, R. A.

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

Palik, E. D.

E. D. Palik, Handbook of Optical Constants of Solids (Academic Press, New York, 1985), Vol. 4.

Park, J. S.

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

Pei, Z. L.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Pertsch, T.

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Peumans, P.

J. Y. Lee, S. T. Connor, Y. Cui, and P. Peumans, “Solution-processed metal nanowire mesh transparent electrodes,” Nano Lett.8, 689–692 (2008).
[CrossRef] [PubMed]

Polman, A.

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

H. A. Atwater and A. Polman, “Plasmonics for improved photovoltaic devices,” Nat. Mater.9, 205–213 (2010).
[CrossRef] [PubMed]

S. Mokkapati, F. J. Beck, A. Polman, and K. R. Catchpole, “Designing periodic arrays of metal nanoparticles for light-trapping applications in solar cells,” Appl. Phys. Lett.95, 053115 (2009).
[CrossRef]

Poon, A. W.

Raman, A.

A. Raman, Z. Yu, and S. Fan, “Dielectric nanostructures for broadband light trapping in organic solar cells,” Opt. Express19, 19015–19026 (2011).
[CrossRef] [PubMed]

Z. Yu, A. Raman, and S. Fan, “Fundamental limit of nanophotonic light trapping in solar cells,” Proc. Natl. Acad. Sci. USA107, 17491–17496 (2010).
[CrossRef] [PubMed]

Rech, B.

J. Muller, B. Rech, J. Springer, and M. Vanecek, “TCO and light trapping in silicon thin film solar cells,” Sol. Energy77, 917–930 (2004).
[CrossRef]

Rivas, J. G.

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

Rockstuhl, C.

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Salleo, A.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Schropp, R. E. I.

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

Schuller, J. A.

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

J. A. Schuller, T. Taubner, and M. L. Brongersma, “Optical antenna thermal emitters,” Nat. Photonics3, 658–661 (2009).
[CrossRef]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

Soderstrom, K.

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

Springer, J.

J. Muller, B. Rech, J. Springer, and M. Vanecek, “TCO and light trapping in silicon thin film solar cells,” Sol. Energy77, 917–930 (2004).
[CrossRef]

Sun, C.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Sun, X. W.

X. W. Sun and H. S. Kwok, “Optical properties of epitaxially grown zinc oxide films on sapphire by pulsed laser deposition,” J. Appl. Phys.86, 408–411 (1999).
[CrossRef]

Taubner, T.

J. A. Schuller, T. Taubner, and M. L. Brongersma, “Optical antenna thermal emitters,” Nat. Photonics3, 658–661 (2009).
[CrossRef]

Vahala, K.

K. Vahala, Optical Microcavities (World Scientific, New Jersey, 2004).
[CrossRef]

van Lare, M. C.

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

Vanecek, M.

J. Muller, B. Rech, J. Springer, and M. Vanecek, “TCO and light trapping in silicon thin film solar cells,” Sol. Energy77, 917–930 (2004).
[CrossRef]

Vasudev, A. P.

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

Verschuuren, M. A.

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

Wen, L. S.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

White, J.

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

White, J. S.

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

Yu, Z.

A. Raman, Z. Yu, and S. Fan, “Dielectric nanostructures for broadband light trapping in organic solar cells,” Opt. Express19, 19015–19026 (2011).
[CrossRef] [PubMed]

Z. Yu, A. Raman, and S. Fan, “Fundamental limit of nanophotonic light trapping in solar cells,” Proc. Natl. Acad. Sci. USA107, 17491–17496 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

Zhang, G. P.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Zhang, X. B.

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Adv. Mater.

R. A. Pala, J. White, E. Barnard, J. Liu, and M. L. Brongersma, “Design of plasmonic thin-film solar cells with broadband absorption enhancements,” Adv. Mater.21, 3504–3509 (2009).
[CrossRef]

J. Grandidier, D. M. Callahan, J. N. Munday, and H. A. Atwater, “Light absorption enhancement in thin-film solar cells using whispering gallery modes in dielectric nanospheres,” Adv. Mater.23, 1272–1276 (2011).
[CrossRef] [PubMed]

Appl. Phys. Lett.

C. Rockstuhl, F. Lederer, K. Bittkau, T. Beckers, and R. Carius, “The impact of intermediate reflectors on light absorption in tandem solar cells with randomly textured surfaces,” Appl. Phys. Lett.95, 211101 (2009).
[CrossRef]

S. Mokkapati, F. J. Beck, A. Polman, and K. R. Catchpole, “Designing periodic arrays of metal nanoparticles for light-trapping applications in solar cells,” Appl. Phys. Lett.95, 053115 (2009).
[CrossRef]

J. Appl. Phys.

X. W. Sun and H. S. Kwok, “Optical properties of epitaxially grown zinc oxide films on sapphire by pulsed laser deposition,” J. Appl. Phys.86, 408–411 (1999).
[CrossRef]

J. Electron. Mater.

L. Goris, R. Noriega, M. Donovan, J. Jokisaari, G. Kusinski, and A. Salleo, “Intrinsic and doped zinc oxide nanowires for transparent electrode fabrication via low-temperature solution synthesis,” J. Electron. Mater.38, 586–595 (2009).
[CrossRef]

Nano Lett.

J. Y. Lee, S. T. Connor, Y. Cui, and P. Peumans, “Solution-processed metal nanowire mesh transparent electrodes,” Nano Lett.8, 689–692 (2008).
[CrossRef] [PubMed]

V. E. Ferry, M. A. Verschuuren, M. C. van Lare, R. E. I. Schropp, H. A. Atwater, and A. Polman, “Optimized spatial correlations for broadband light trapping nanopatterns in high efficiency ultrathin film a-Si:H solar cells,” Nano Lett.11, 4239–4245 (2011).
[CrossRef] [PubMed]

O. L. Muskens, S. L. Diedenhofen, B. C. Kaas, R. E. Algra, E. Bakkers, J. G. Rivas, and A. Lagendijk, “Large photonic strength of highly tunable resonant nanowire materials,” Nano Lett.9, 930–934 (2009).
[CrossRef] [PubMed]

L. Cao, P. Fan, E. S. Barnard, A. M. Brown, and M. L. Brongersma, “Tuning the color of silicon nanowires,” Nano Lett.10, 2649–2654 (2010).
[CrossRef] [PubMed]

L. Cao, P. Fan, A. P. Vasudev, J. S. White, Z. Yu, W. Cai, J. A. Schuller, S. Fan, and M. L. Brongersma, “Semiconductor nanowire optical antenna solar absorbers,” Nano Lett.10, 439–445 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. Park, P. Fan, B. Clemens, and M. L. Brongersma, “Resonant germanium nanoantenna photodetectors,” Nano Lett.10, 1229–1233 (2010).
[CrossRef] [PubMed]

Nat. Mater.

H. A. Atwater and A. Polman, “Plasmonics for improved photovoltaic devices,” Nat. Mater.9, 205–213 (2010).
[CrossRef] [PubMed]

L. Cao, J. S. White, J. S. Park, J. A. Schuller, B. M. Clemens, and M. L. Brongersma, “Engineering light absorption in semiconductor nanowire devices,” Nat. Mater.8, 643–647 (2009).
[CrossRef] [PubMed]

Nat. Photonics

C. Battaglia, J. Escarre, K. Soderstrom, M. Charriere, M. Despeisse, F. Haug, and C. Ballif, “Nanomoulding of transparent zinc oxide electrodes for efficient light trapping in solar cells,” Nat. Photonics5, 535–538 (2011).
[CrossRef]

J. A. Schuller, T. Taubner, and M. L. Brongersma, “Optical antenna thermal emitters,” Nat. Photonics3, 658–661 (2009).
[CrossRef]

Opt. Express

Opt. Lett.

Phys. Status Solidi A

M. Kroll, S. Fahr, C. Helgert, C. Rockstuhl, F. Lederer, and T. Pertsch, “Employing dielectric diffractive structures in solar cells–a numerical study,” Phys. Status Solidi A205, 2777–2795 (2008).
[CrossRef]

Proc. Natl. Acad. Sci. USA

Z. Yu, A. Raman, and S. Fan, “Fundamental limit of nanophotonic light trapping in solar cells,” Proc. Natl. Acad. Sci. USA107, 17491–17496 (2010).
[CrossRef] [PubMed]

Sol. Energy

J. Muller, B. Rech, J. Springer, and M. Vanecek, “TCO and light trapping in silicon thin film solar cells,” Sol. Energy77, 917–930 (2004).
[CrossRef]

Thin Solid Films

Z. L. Pei, X. B. Zhang, G. P. Zhang, J. Gong, C. Sun, R. F. Huang, and L. S. Wen, “Transparent conductive ZnO: Al thin films deposited on flexible substrates prepared by direct current magnetron sputtering,” Thin Solid Films497, 20–23 (2006).
[CrossRef]

Other

E. Hecht, Optics (Addison-Wesley, Massachusetts, 2002).

C. F. Bohren and D. R. Huffman, Absorption and Scattering of Light by Small Particles (Wiley-VCH, New York, 2010).

K. Vahala, Optical Microcavities (World Scientific, New Jersey, 2004).
[CrossRef]

H. A. Haus, Waves and Fields in Optoelectronics (Prentice-Hall, New Jersey, 1984).

J. W. Goodman, Introduction to Fourier Optics (Roberts & Co., Colorado, 2005).

E. D. Palik, Handbook of Optical Constants of Solids (Academic Press, New York, 1985), Vol. 4.

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Figures (5)

Fig. 1
Fig. 1

Schematic of our model structure consisting of a periodic array of transparent conductive oxide (ZnO) beams placed on top of a thin crystalline Si layer. The structure is supported by a silica substrate. We characterize the square beams by their width, w, and we define the array by a grating pitch or a reciprocal lattice vector, G.

Fig. 2
Fig. 2

Spectral dependence of the scattering efficiency, Qsca, for square cross-section ZnO nanobeams in air. The dimensions, w, of the beams are indicated on the right-hand side and the spectra for different sizes are vertically offset in increments of 3 for clarity. The spectral dependence of the AM 1.5 solar irradiance is shown in the background (grey) for reference.

Fig. 3
Fig. 3

A ZnO nanobeam array significantly enhances the absorption in a silicon layer at almost all wavelengths. (a) The AM 1.5 solar irradiance (orange) provides the spectral power density of sunlight and the spectral response of the silicon/silica stack (black) diminishes with longer wavelength, excepting a Fabry-Perot peak near 450 nm. (b) The absorption enhancement provided by the nanobeam array under both TE (blue) and TM (red) illumination exceeds that of a planar antireflection coating (green). (c) The product of the solar irradiance, the spectral response, and the absorption enhancement, integrated over wavelength, yields the short-circuit current density value. We find that the short-circuit current density generated in the silicon layer by the ZnO nanobeam array enhances that of the bare structure by 87% for unpolarized light, in comparison to the 46% enhancement gained using a planar antireflection coating. The unpolarized light enhancement was calculated by averaging the TE and TM enhancements, 78% and 95% respectively.

Fig. 4
Fig. 4

Absorption enhancement maps and field intensity plots reveal the physics behind the absorption enhancements. (a,b) Absorption enhancement maps for TE (a) and TM (b) polarized illumination contain two classes of features: broad, G-invariant regions and narrow, G-dependent bands. The former can be assigned to Mie-like scattering resonances associated with individual ZnO nanobeams while the latter derive from coupling of light into diffracted and wave-guided modes by the array of nanobeams. (c) Magnetic field distribution for a Mie-like resonance, taken from the location marked C in (a). (d) Electric field distribution for a diffracted mode, taken from the location marked D in (b). (e) Electric field distribution for a wave-guided mode, taken from the location marked E in (b).

Fig. 5
Fig. 5

An optimized ZnO nanobeam array improves the optical performance of a realistic amorphous silicon solar cell. (a) An amorphous silicon solar cell stack consisting of an Al reflector, a ZnO spacer layer, a 300 nm a-Si layer and an array of ZnO nanobeams. The square ZnO nanobeams have a width of 240 nm and the array pitch is 408 nm. (b) TE and TM absorption maps for this structure consist of the same features as before, implying Mie-like resonances and the coupling of light into diffracted and wave-guided modes constitute the absorption enhancement physics. (c) The ZnO nanobeam array (blue) improves upon the performance of an optimized planar ZnO film (green) in terms of allowing the a-Si film to reach its absorbing capacity, defined as full absorption of the above-band gap portion of the AM 1.5 spectrum (orange). (d) The ZnO nanobeams improve the short-circuit current density of an optimal solar cell with a planar ZnO layer from 19.9 mA/cm2 to 21.1 mA/cm2. The maximum achievable short-circuit current density is 26.0 mA/cm2, assuming complete absorption of the above-band gap AM 1.5 spectrum.

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