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Energy Express

Energy Express

  • Editor: Bernard Kippelen
  • Vol. 20, Iss. S3 — May. 7, 2012
  • pp: A431–A440

Indium tin oxide subwavelength nanostructures with surface antireflection and superhydrophilicity for high-efficiency Si-based thin film solar cells

Jung Woo Leem and Jae Su Yu  »View Author Affiliations

Optics Express, Vol. 20, Issue S3, pp. A431-A440 (2012)

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We fabricated the parabola-shaped subwavelength grating (SWG) nanostructures on indium tin oxide (ITO) films/Si and glass substrates using laser interference lithography, dry etching, and subsequent re-sputtering processes. The efficiency enhancement of an a-Si:H/μc-Si:H tandem thin film solar cell was demonstrated theoretically by applying the experimentally measured data of the fabricated samples to the simulation parameters. Their wetting behaviors and effective electrical properties as well as optical reflectance properties of ITO SWGs, together with theoretical prediction using a rigorous coupled-wave analysis method, were investigated. For the parabola-shaped ITO SWG/ITO film, the solar weighted reflectance (SWR) value was ~10.2% which was much lower than that (i.e., SWR~20%) of the conventional ITO film, maintaining the SWR values less than 19% up to a high incident angle of 70° over a wide wavelength range of 300-1100 nm. Also, the ITO SWG with a superhydrophilic surface property (i.e., water contact angle of 6.2°) exhibited an effective resistivity of 2.07 × 10−3 Ω-cm. For the a-Si:H/μc-Si:H tandem thin film solar cell structure incorporated with the parabola-shaped ITO SWG/ITO film as an antireflective electrode layer, the conversion efficiency (η) of 13.7% was theoretically obtained under AM1.5g illumination, indicating an increased efficiency by 1.4% compared to the device with the conventional ITO film (i.e., η = 12.3%).

© 2012 OSA

OCIS Codes
(040.5350) Detectors : Photovoltaic
(160.4760) Materials : Optical properties
(220.4241) Optical design and fabrication : Nanostructure fabrication

ToC Category:

Original Manuscript: March 7, 2012
Revised Manuscript: April 16, 2012
Manuscript Accepted: April 24, 2012
Published: May 3, 2012

Jung Woo Leem and Jae Su Yu, "Indium tin oxide subwavelength nanostructures with surface antireflection and superhydrophilicity for high-efficiency Si-based thin film solar cells," Opt. Express 20, A431-A440 (2012)

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  1. T. Söderström, F. J. Haug, X. Niquille, V. Terrazzoni, and C. Ballif, “Asymmetric intermediate reflector for tandem micromorph thin film silicon solar cells,” Appl. Phys. Lett.94(6), 063501 (2009). [CrossRef]
  2. J. Y. Huang, C. Y. Lin, C. H. Shen, J. M. Shieh, and B. T. Dai, “Low cost high-efficiency amorphous silicon solar cells with improved light-soaking stability,” Sol. Energy Mater. Sol. Cells98, 277–282 (2012). [CrossRef]
  3. H. Sai, H. Fujii, K. Arafune, Y. Ohshita, Y. Kanamori, H. Yugami, and M. Yamaguchi, “Wide-angle antireflection effect of subwavelength structures for solar cells,” Jpn. J. Appl. Phys.46(6A), 3333–3336 (2007). [CrossRef]
  4. J. Y. Chen, W. L. Chang, C. K. Huang, and K. W. Sun, “Biomimetic nanostructured antireflection coating and its application on crystalline silicon solar cells,” Opt. Express19(15), 14411–14419 (2011). [CrossRef] [PubMed]
  5. Y. M. Song, J. S. Yu, and Y. T. Lee, “Antireflective submicrometer gratings on thin-film silicon solar cells for light-absorption enhancement,” Opt. Lett.35(3), 276–278 (2010). [CrossRef] [PubMed]
  6. M. Y. Chiu, C. H. Chang, M. A. Tsai, F. Y. Chang, and P. Yu, “Improved optical transmission and current matching of a triple-junction solar cell utilizing sub-wavelength structures,” Opt. Express18(S3Suppl 3), A308–A313 (2010). [CrossRef] [PubMed]
  7. P. B. Clapham and M. C. Hutley, “Reduction of lens reflexion by the ‘Moth Eye’ principle,” Nature244(5414), 281–282 (1973). [CrossRef]
  8. D. G. Stavenga, S. Foletti, G. Palasantzas, and K. Arikawa, “Light on the moth-eye corneal nipple array of butterflies,” Proc. Biol. Sci.273(1587), 661–667 (2006). [CrossRef] [PubMed]
  9. Y. M. Song, S. J. Jang, J. S. Yu, and Y. T. Lee, “Bioinspired parabola subwavelength structures for improved broadband antireflection,” Small6(9), 984–987 (2010). [CrossRef] [PubMed]
  10. Y. H. Ko and J. S. Yu, “Design of hemi-urchin shaped ZnO nanostructures for broadband and wide-angle antireflection coatings,” Opt. Express19(1), 297–305 (2011). [CrossRef] [PubMed]
  11. J. W. Leem, D. H. Joo, and J. S. Yu, “Biomimetic parabola-shaped AZO subwavelength grating structures for efficient antireflection of Si-based solar cells,” Sol. Energy Mater. Sol. Cells95(8), 2221–2227 (2011). [CrossRef]
  12. A. Fernandez, J. Y. Decker, S. M. Herman, D. W. Phillion, D. W. Sweeney, and M. D. Perry, “Methods for fabricating arrays of holes using interference lithography,” J. Vac. Sci. Technol. B15(6), 2439–2443 (1997). [CrossRef]
  13. S. Y. Lien, B. R. Wu, J. C. Liu, and D. S. Wuu, “Fabrication and characteristics of n-Si/c-Si/p-Si heterojunction solar cells using hot-wire CVD,” Thin Solid Films516(5), 747–750 (2008). [CrossRef]
  14. Q. H. Fan, C. Chen, X. Liao, X. Xiang, X. Cao, W. Ingler, N. Adiga, and X. Deng, “Spectroscopic aspects of front transparent conductive films for a-Si thin film solar cells,” J. Appl. Phys.107(3), 034505 (2010). [CrossRef]
  15. S. Y. Lien, “Characterization and optimization of ITO thin films for application in heterojunction silicon solar cells,” Thin Solid Films518(21), S10–S13 (2010). [CrossRef]
  16. J. W. Leem and J. S. Yu, “Influence of oblique-angle sputtered transparent conducting oxides on performance of Si-based thin film solar cells,” Phys. Status Solidi. A208(9), 2220–2225 (2011). [CrossRef]
  17. J. Yang and J. M. Kleijn, “Order in phospholipid Langmuir-Blodgett layers and the effect of the electrical potential of the substrate,” Biophys. J.76(1), 323–332 (1999). [CrossRef] [PubMed]
  18. A. Fujishima, T. N. Rao, and D. A. Tryk, “Titanium dioxide photocatalysis,” J. Photochem. Photobiol. Photochem. Rev.1(1), 1–21 (2000). [CrossRef]
  19. R. N. Wenzel, “Resistance of solid surface to wetting by water,” Ind. Eng. Chem.28(8), 988–994 (1936). [CrossRef]
  20. C. H. Chang, M. H. Hsu, P. C. Tseng, P. Yu, W. L. Chang, W. C. Sun, and W. C. Hsu, “Enhanced angular characteristics of indium tin oxide nanowhisker-coated silicon solar cells,” Opt. Express19(S3Suppl 3), A219–A224 (2011). [CrossRef] [PubMed]
  21. C. O’Dwyer, M. Szachowicz, G. Visimberga, V. Lavayen, S. B. Newcomb, and C. M. Torres, “Bottom-up growth of fully transparent contact layers of indium tin oxide nanowires for light-emitting devices,” Nat. Nanotechnol.4(4), 239–244 (2009). [CrossRef] [PubMed]
  22. Y. M. Song, E. S. Choi, G. C. Park, C. Y. Park, S. J. Jang, and Y. T. Lee, “Disordered antireflective nanostructures on GaN based light-emitting diodes using Ag nanoparticles for improved light extraction efficiency,” Appl. Phys. Lett.97(9), 093110 (2010). [CrossRef]
  23. S. Michael and A. Bates, “The design and optimization of advanced multijunction solar cells using the Silvaco ATLAS software package,” Sol. Energy Mater. Sol. Cells87(1-4), 785–794 (2005). [CrossRef]
  24. S. T. Chang, M. Tang, R. Y. He, W. C. Wang, Z. Pei, and C. Y. Kung, “TCAD simulation of hydrogenated amorphous silicon-carbon/microcrystalline-silicon/hydrogenated amorphous silicon-germanium PIN solar cells,” Thin Solid Films518(6), S250–S254 (2010). [CrossRef]
  25. L. J. van der Pauw, “A method of measuring specific resistivity and Hall effect of disces of arbitrary shape,” Philips Res. Rep.13, 1–9 (1958).
  26. M. G. Moharam and T. K. Gaylord, “Rigorous coupled-wave analysis of planar-grating diffraction,” J. Opt. Soc. Am.71(7), 811–818 (1981). [CrossRef]
  27. S. Y. Myong, K. Sriprapha, S. Miyajima, M. Konagai, and A. Yamada, “High efficiency protocrystalline silicon/microcrystalline silicon tandem cell with zinc oxide intermediate layer,” Appl. Phys. Lett.90(26), 263509 (2007). [CrossRef]
  28. NREL’s Renewable Resource Data Center, http://rredc.nrel.gov/solar/spectra , Accessed 15 Jan. (2012).
  29. ATLAS User's Manual, Silvaco international, Feb (2012).
  30. J. W. Leem and J. S. Yu, “Glancing angle deposited ITO films for efficiency enhancement of a-Si:H/μc-Si:H tandem thin film solar cells,” Opt. Express19(S3Suppl 3), A258–A268 (2011). [CrossRef] [PubMed]
  31. S. H. Lin, Y. C. Chan, D. P. Webb, and Y. W. Lam, “Optical characterization of hydrogenated amorphous silicon thin films deposited at high rate,” J. Electron. Mater.28(12), 1452–1456 (1999). [CrossRef]
  32. Y. Zhong, Y. C. Shin, C. M. Kim, B. G. Lee, E. H. Kim, Y. J. Park, K. M. A. Sobahan, C. K. Hwangbo, Y. P. Lee, and T. G. Kim, “Optical and electrical properties of indium tin oxide thin films with tilted and spiral microstructures prepared by oblique angle deposition,” J. Mater. Res.23(09), 2500–2505 (2008). [CrossRef]
  33. SOPRA, http://www.sopra-sa.com , Accessed 1 Dec. (2011).
  34. J. W. Leem, Y. P. Kim, and J. S. Yu, “Tunable behavior of reflectance minima in periodic Ge submicron grating structures,” J. Opt. Soc. Am. B29(3), 357–362 (2012). [CrossRef]
  35. E. Hecht, Optics, 4th ed. (Addison Wesley, 2002).
  36. E. B. Grann, M. G. Varga, and D. A. Pommet, “Optimal design for antireflective tapered two-dimensional subwavelength grating structures,” J. Opt. Soc. Am. A12(2), 333–339 (1995). [CrossRef]
  37. C. Ye, S. S. Pan, X. M. Teng, H. T. Fan, and G. H. Li, “Preparation and optical properties of nanocrystalline thin films in the ZnO-TiO2 system,” Appl. Phys. A90(2), 375–378 (2007). [CrossRef]

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