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Author Eyderman, Sergey ♦ John, Sajeev ♦ Hafez, M. ♦ Al-Ameer, S. S. ♦ Al-Harby, T. S. ♦ Al-Hadeethi, Y. ♦ Bouwes, D. M.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS ♦ ABSORPTION ♦ CRYSTALS ♦ CURRENT DENSITY ♦ ETCHING ♦ FABRICATION ♦ NUMERICAL SOLUTION ♦ OPTIMIZATION ♦ SILICON ♦ SOLAR CELLS ♦ TETRAGONAL LATTICES ♦ TRAPPING ♦ VISIBLE RADIATION ♦ WAVELENGTHS
Abstract We demonstrate, by numerical solution of Maxwell's equations, near-perfect solar light-trapping and absorption over the 300–1100 nm wavelength band in silicon photonic crystal (PhC) architectures, amenable to fabrication by wet-etching and requiring less than 10 μm (equivalent bulk thickness) of crystalline silicon. These PhC's consist of square lattices of inverted pyramids with sides comprised of various (111) silicon facets and pyramid center-to-center spacing in the range of 1.3–2.5 μm. For a wet-etched slab with overall height H = 10 μm and lattice constant a = 2.5 μm, we find a maximum achievable photo-current density (MAPD) of 42.5 mA/cm{sup 2}, falling not far from 43.5 mA/cm{sup 2}, corresponding to 100% solar absorption in the range of 300–1100 nm. We also demonstrate a MAPD of 37.8 mA/cm{sup 2} for a thinner silicon PhC slab of overall height H = 5 μm and lattice constant a = 1.9 μm. When H is further reduced to 3 μm, the optimal lattice constant for inverted pyramids reduces to a = 1.3 μm and provides the MAPD of 35.5 mA/cm{sup 2}. These wet-etched structures require more than double the volume of silicon, in comparison to the overall mathematically optimum PhC structure (consisting of slanted conical pores), to achieve the same degree of solar absorption. It is suggested these 3–10 μm thick structures are valuable alternatives to currently utilized 300 μm-thick textured solar cells and are suitable for large-scale fabrication by wet-etching.
ISSN 00218979
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-07-14
Publisher Place United States
Journal Journal of Applied Physics
Volume Number 118
Issue Number 2


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