Photonic and plasmonic crystal based enhancement of solar cells - Theory of overcoming the Lambertian limit

TitlePhotonic and plasmonic crystal based enhancement of solar cells - Theory of overcoming the Lambertian limit
Publication TypeJournal Article
Year of Publication2012
AuthorsBiswas R, Xu C
Journal TitleJournal of Non-Crystalline Solids
Volume358
Pages2289-2294
Date Published09
Type of ArticleArticle; Proceedings Paper
ISBN Number0022-3093
Accession NumberWOS:000310394700087
KeywordsEFFICIENCY, Light trapping, silicon, solar cell
Abstract

We develop a new conformal nc-Si solar cell architecture that has a periodic plasmonic back-reflector of tapered nano-pillars. Using rigorous scattering matrix simulations, we show that the optimized solar architecture has absorption that can exceed the classical 4n(2) limit, or the Lambertian limit of absorption by a randomly roughened back-reflector, for common thicknesses of the nc-Si absorber layer upto 1500 nm in thickness. The optimized solar architecture has pitch between 500 and 900 nm and tapered pillar heights of similar to 200 nm. The conformal solar cell geometry minimizes the reflection loss at the top surface. The enhancement over the classical limit is provided by light concentration and waveguide modes or diffraction resonances within the absorber layer. Nc-Si cells of 1000 nm thickness may generate short circuit currents in excess of 32 mA/cm(2), where the enhancement is more than 60% relative to a flat silver back-reflector. Sources of losses in solar cells and are identified. (C) 2011 Elsevier B.V. All rights reserved.

URL<Go to ISI>://WOS:000310394700087
DOI10.1016/j.jnoncrysol.2011.12.011
Alternate JournalJ. Non-Cryst. Solids