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Energy Express

  • Editor: Bernard Kippelen
  • Vol. 18, Iss. S2 — Jun. 21, 2010
  • pp: A133–A138

Enhanced light trapping in thin-film solar cells by a directionally selective filter

Carolin Ulbrich, Marius Peters, Benedikt Bläsi, Thomas Kirchartz, Andreas Gerber, and Uwe Rau  »View Author Affiliations

Optics Express, Vol. 18, Issue S2, pp. A133-A138 (2010)

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A directionally selective multilayer filter is applied to a hydrogenated amorphous silicon solar cell to improve the light trapping. The filter prevents non-absorbed long-wavelength photons from leaving the cell under oblique angles leading to an enhancement of the total optical path length for weakly absorbed light within the device by a factor of κr = 3.5. Parasitic absorption in the contact layers limits the effective path length improvement for the photovoltaic quantum efficiency to a factor of κEQE = 1.5. The total short-circuit current density increases by ΔJsc = 0.2 mAcm−2 due to the directional selectivity of the Bragg-like filter.

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OCIS Codes
(220.1770) Optical design and fabrication : Concentrators
(230.1480) Optical devices : Bragg reflectors
(310.1620) Thin films : Interference coatings
(350.6050) Other areas of optics : Solar energy
(310.6188) Thin films : Spectral properties

ToC Category:
Thin Films

Original Manuscript: April 9, 2010
Revised Manuscript: May 12, 2010
Manuscript Accepted: May 12, 2010
Published: May 19, 2010

Carolin Ulbrich, Marius Peters, Benedikt Bläsi, Thomas Kirchartz, Andreas Gerber, and Uwe Rau, "Enhanced light trapping in thin-film solar cells by a directionally selective filter," Opt. Express 18, A133-A138 (2010)

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