Effect of Sunlight Polarization on the Absorption Efficiency of V-shaped Organic Solar Cells

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  • ABSTRACT

    We numerically investigate the effect of sunlight polarization on the absorption efficiency of V-shaped organic solar cells (VOSCs) using the finite element method (FEM). The spectral distribution of absorbance and the spatial distribution of power dissipation are calculated as a function of the folding angle for s-and p-polarized light. The absorption enhancement caused by the light-trapping effect was more pronounced for s-polarized light at folding angles smaller than 20°, where s-polarized light has a relatively larger reflectance than p-polarized light. On the other hand, the absorption efficiency for p-polarized light is relatively larger for folding angles larger than 20°, where the smaller reflectance at the interface of the VOSC is more important in obtaining high absorption efficiency.


  • KEYWORD

    Organic solar cell , Optical modeling , Light trapping , Finite element method

  • 1. Coakley K. M., McGehee M. D. 2004 “Conjugated polymer photovoltaic cells,” [Chem. Mater.] Vol.16 P.4533-4542 google
  • 2. Hoppe H., Sariciftci N. S. 2004 “Organic solar cells: An overview,” [J. Mater Res.] Vol.19 P.1924-1945 google
  • 3. Brabec C. J. 2004 “Organic solar cells: An overview,” [Sol. Energy Mater. Sol. Cells] Vol.83 P.273-292 google
  • 4. Peumans P., Bulovic V., Forrest S. R. 2000 “Efficient photon harvesting at high optical intensities in ultrathin organic double-heterostructure photovoltaic diodes,” [Appl. Phys. Lett.] Vol.76 P.2650 google
  • 5. Peumans P., Yakimov A., Forrest S. R. 2003 “Small molecular weight organic thin-film photodetectors and solar cells,” [J. Appl. Phys.] Vol.93 P.3693 google
  • 6. Roman L. S., Inganas O., Granlund T., Nyberg T., Svensson M., Andersson M. R., Hummelen J. C. 2000 “Trapping light in polymer photodiodes with soft embossed gratings,” [Adv. Mater.] Vol.12 P.189-195 google
  • 7. Niggemann M., Glatthaar M., Gomber A., Hinsch A., Wittwer V. 2004 “Diffraction gratings and buried nano-electrodes-architectures for organic solar cells,” [Thin Solid Films] Vol.451-452 P.619-623 google
  • 8. Tvingstedt K., Tormen M., Businaro L., Inganas O. 2006 “Light confinement in thin film organic photovoltaic cells,” [Proc. SPIE] Vol.6197 P.61970C google
  • 9. Tvingstedt K., Andersson V., Zhang F. L., Inganas O. 2007 “Folded reflective tandem polymer solar cell doubles efficiency,” [Appl. Phys. Lett.] Vol.91 P.123514 google
  • 10. Rim S.-B., Zhao S., Scully S. R., McGehee M. D., Peumans P. 2007 “An effective light trapping configuration for thin-film solar cells,” [Appl. Phys. Lett.] Vol.91 P.243501 google
  • 11. Andersson V., Tvingstedt K., Inganas O. 2008 “Optical modeling of a folded organic solar cell,” [J. Appl. Phys.] Vol.103 P.094520 google
  • 12. Andersson B. V., Persson N.-K., Inganas O. 2008 “Comparative study of organic thin film tandem solar cells in alternative geometries,” [J. Appl. Phys.] Vol.104 P.124508 google
  • 13. Lee S., Jeong I., Kim H. P., Hwang S. Y., T. J. Kim, Kim Y. D., Jang J., Kim J. 2013 “Effect of incidence angle and polarization on the optimized layer structure of organic solar cells,” [Sol. Energy Mater. Sol. Cells] Vol.118 P.9-17 google
  • 14. Pettersson L. A. A., Roman L. S., Inganas O. 1999 “Modeling photocurrent action spectra of photovoltaic devices based on organic thin films,” [J. Appl. Phys.] Vol.86 P.487-496 google
  • 15. Cheyns D., Rand B. P., Verreet B., Genoe J., Poortmans J., Heremans P. 2008 “The angular response of ultrathin film organic solar cells,” [Appl. Phys. Lett.] Vol.92 P.243310 google
  • 16. Meyer A., Ade H. 2009 “The effect of angle of incidence on the optical field distribution within thin film organic solar cells,” [J. Appl. Phys.] Vol.106 P.113101 google
  • 17. Jung S., Kim K.-Y., Lee Y.-I., Youn J.-H., Moon H.-T., Jang J., Kim J. 2011 “Optical modeling and analysis of organic solar cells with coherent multilayers and incoherent glass substrate using generalized transfer matrix method,” [Jpn. J. Appl. Phys.] Vol.50 P.122301 google
  • 18. Kim J., Jung S., Jeong I. 2012 “Optical modeling for polarizationdependent optical power dissipation of thin-film organic solar cells at oblique incidence,” [J. Opt. Soc. Korea] Vol.16 P.6-12 google
  • 19. Jung S., Lee Y.-I., Youn J.-H., Moon H.-T., Jang J., Kim J. 2013 “Effect of the active-layer thickness on the shortcircuit current analyzed using the generalized transfer matrix method,” [J. Inf. Display] Vol.14 P.7-11 google
  • 20. Kang K., Lee S., Kim J. 2013 “Effect of an incoherent glass substrate on the absorption efficiency of organic solar cells at oblique incidence analyzed by the transfer matrix method with a glass factor,” [Jpn. J. Appl. Phys.] Vol.52 P.052301 google
  • 21. 2012 COMSOL Multiphysics, Version 4.3a google
  • [FIG. 1.] Schematic diagram of the device structure along with material’s composition and thickness of each layer. The plane wave is assumed to enter the OSC structure from the air at the uppermost boundary. The direction of the electric field oscillations is perpendicular (s-polarization) or parallel (ppolarization) to the incident plane. Two arms of the VOSC are tilted to the normal incident light with a folding angle of α.
    Schematic diagram of the device structure along with material’s composition and thickness of each layer. The plane wave is assumed to enter the OSC structure from the air at the uppermost boundary. The direction of the electric field oscillations is perpendicular (s-polarization) or parallel (ppolarization) to the incident plane. Two arms of the VOSC are tilted to the normal incident light with a folding angle of α.
  • [FIG. 2.] Calculated absorptance spectra in the active layer (P3HT:PCBM) of the VSOC for various folding angles. As the folding angle decreases, the absorptance increases and becomes saturated.
    Calculated absorptance spectra in the active layer (P3HT:PCBM) of the VSOC for various folding angles. As the folding angle decreases, the absorptance increases and becomes saturated.
  • [FIG. 3.] The extinction coefficient spectra of the active layer (P3HT : PCBM), which has the peak value at the wavelength of 500 nm and shows the ripple between 500 and 600 nm.
    The extinction coefficient spectra of the active layer (P3HT : PCBM), which has the peak value at the wavelength of 500 nm and shows the ripple between 500 and 600 nm.
  • [FIG. 4.] The spatial distribution of the power dissipation in the VOSC at the folding angle of α = (a) 20°, (b) 45°, and (c) 70° for s-polarized light. The spatial distribution of the power dissipation is obtained by taking the summation over the whole wavelength range.
    The spatial distribution of the power dissipation in the VOSC at the folding angle of α = (a) 20°, (b) 45°, and (c) 70° for s-polarized light. The spatial distribution of the power dissipation is obtained by taking the summation over the whole wavelength range.
  • [FIG. 5.] The spatial distribution of the power dissipation in the VOSC at the folding angle of α = (a) 20°, (b) 45°, and (c) 70° for p-polarized light. The spatial distribution of the power dissipation is obtained by taking the summation over the whole wavelength range.
    The spatial distribution of the power dissipation in the VOSC at the folding angle of α = (a) 20°, (b) 45°, and (c) 70° for p-polarized light. The spatial distribution of the power dissipation is obtained by taking the summation over the whole wavelength range.
  • [FIG. 6.] Calculated reflectance spectra at the interface of the VOCS at the folding angle of α = 20°, 45°, and 70° for s- and p-polarized light. For the folding angles of α = 20°, 45°, and 70°, the incidence angle at the interface of the VOSC corresponds to α = 70°, 45°, and 20° in terms of the oblique incidence for planar solar cells.
    Calculated reflectance spectra at the interface of the VOCS at the folding angle of α = 20°, 45°, and 70° for s- and p-polarized light. For the folding angles of α = 20°, 45°, and 70°, the incidence angle at the interface of the VOSC corresponds to α = 70°, 45°, and 20° in terms of the oblique incidence for planar solar cells.
  • [FIG. 7.] Calculation results of polarization-dependent absorptance spectra in the active layer of the VOSC at the folding angles of α = 20°, 45°, and 70°. Both polarizations have relatively high absorptance at the small folding angle due to the enhanced light trapping effect.
    Calculation results of polarization-dependent absorptance spectra in the active layer of the VOSC at the folding angles of α = 20°, 45°, and 70°. Both polarizations have relatively high absorptance at the small folding angle due to the enhanced light trapping effect.
  • [FIG. 8.] Calculated total absorptance of the VOCS as a function of the folding angle α for s- and p-polarized light
    Calculated total absorptance of the VOCS as a function of the folding angle α for s- and p-polarized light
  • [FIG. 9.] (a) Optical spectra of the AM 1.5 sunlight. (b) Calculated solar absorptance of the VOSC as a function of the folding angle α for s- and p-polarized light.
    (a) Optical spectra of the AM 1.5 sunlight. (b) Calculated solar absorptance of the VOSC as a function of the folding angle α for s- and p-polarized light.