Comparison of periodic and random structures for scattering in thinfilm microcrystalline silicon solar cells

Peters M, Forberich K, Battaglia C, Aberle AG, Bläsi B (2012)

Publication Type: Conference contribution

Publication year: 2012

Journal

Proceedings of SPIE Society of Photo-optical Instrumentation Engineers (SPIE)

Book Volume: 8438

Conference Proceedings Title: Proceedings of SPIE - The International Society for Optical Engineering

Event location: BEL

ISBN: 9780819491305

DOI: 10.1117/12.921774

Abstract

Random structures are typically used for light trapping in thin-film silicon solar cells. However, theoretically periodic structures can outperform random structures in such applications. In this paper we compare random and periodic structures of similar shape. Both types of structure are based on atomic force microscopy (AFM) scans of a sputtered and etched ZnO layer. The absorption in a solar cell on both structures was calculated and compared to external quantum efficiency (EQE) measurements of samples fabricated on the random texture. Measured and simulated currents were found to be comparable. A scalar scattering approach was used to simulate random structures, the rigorous coupled wave analysis (RCWA) to simulate periodic structures. The length and height of random and periodic structures were scaled and changes in the photocurrent were investigated. A high height/length ratio seems beneficial for periodic and random structures. Very high currents were found for random structures with very high roughness. For periodic structures, current maxima were found for specific periods and heights. An optimized periodic structure had a period of Λ= 534 nm and a depth of d = 277 nm. The photocurrent of this structure was increased by 1.6 mA/cm 2 or 15% relative compared to the initial (random) structure in the spectral range between 600 nm and 900 nm. © 2012 SPIE.

Involved external institutions

Nanyang Technological University (NTU) SG Singapore (SG) École Polytechnique Fédérale de Lausanne (EPFL) CH Switzerland (CH) Fraunhofer-Institut für Solare Energiesysteme (ISE) / Fraunhofer Institute for Solar Energy Systems DE Germany (DE)

How to cite

APA:

Peters, M., Forberich, K., Battaglia, C., Aberle, A.G., & Bläsi, B. (2012). Comparison of periodic and random structures for scattering in thinfilm microcrystalline silicon solar cells. In Proceedings of SPIE - The International Society for Optical Engineering. BEL.

MLA:

Peters, M., et al. "Comparison of periodic and random structures for scattering in thinfilm microcrystalline silicon solar cells." Proceedings of the Photonics for Solar Energy Systems IV, BEL 2012.

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