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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 16, Iss. 13 — Jun. 23, 2008
  • pp: 9332–9343

Rugate filter for light-trapping in solar cells

Stephan Fahr, Carolin Ulbrich, Thomas Kirchartz, Uwe Rau, Carsten Rockstuhl, and Falk Lederer  »View Author Affiliations

Optics Express, Vol. 16, Issue 13, pp. 9332-9343 (2008)

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We suggest a design for a coating that could be applied on top of any solar cell having at least one diffusing surface. This coating acts as an angle and wavelength selective filter, which increases the average path length and absorptance at long wavelengths without altering the solar cell performance at short wavelengths. The filter design is based on a continuous variation of the refractive index in order to minimize undesired reflection losses. Numerical procedures are used to optimize the filter for a 10 µm thick monocrystalline silicon solar cell, which lifts the efficiency above the Auger limit for unconcentrated illumination. The feasibility to fabricate such filters is also discussed, considering a finite available refractive index range.

© 2008 Optical Society of America

OCIS Codes
(040.5350) Detectors : Photovoltaic
(220.1770) Optical design and fabrication : Concentrators
(230.4170) Optical devices : Multilayers
(310.0310) Thin films : Thin films
(350.2460) Other areas of optics : Filters, interference
(350.6050) Other areas of optics : Solar energy

ToC Category:

Original Manuscript: May 1, 2008
Revised Manuscript: June 5, 2008
Manuscript Accepted: June 5, 2008
Published: June 10, 2008

Stephan Fahr, Carolin Ulbrich, Thomas Kirchartz, Uwe Rau, Carsten Rockstuhl, and Falk Lederer, "Rugate filter for light-trapping in solar cells," Opt. Express 16, 9332-9343 (2008)

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