Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications

Michael D. Kelzenberg, Shannon W. Boettcher, Jan A. Petykiewicz, Daniel B. Turner-Evans, Morgan C. Putnam, Emily L. Warren, Joshua M. Spurgeon, Ryan M. Briggs, Nathan S Lewis, Harry A. Atwater

Research output: Contribution to journalArticle

1061 Citations (Scopus)

Abstract

Si wire arrays are a promising architecture for solar-energy-harvesting applications, and may offer a mechanically flexible alternative to Si wafers for photovoltaics. To achieve competitive conversion efficiencies, the wires must absorb sunlight over a broad range of wavelengths and incidence angles, despite occupying only a modest fraction of the arrays volume. Here, we show that arrays having less than 5% areal fraction of wires can achieve up to 96% peak absorption, and that they can absorb up to 85% of day-integrated, above-bandgap direct sunlight. In fact, these arrays show enhanced near-infrared absorption, which allows their overall sunlight absorption to exceed the ray-optics light-trapping absorption limit for an equivalent volume of randomly textured planar Si, over a broad range of incidence angles. We furthermore demonstrate that the light absorbed by Si wire arrays can be collected with a peak external quantum efficiency of 0.89, and that they show broadband, near-unity internal quantum efficiency for carrier collection through a radial semiconductor/liquid junction at the surface of each wire. The observed absorption enhancement and collection efficiency enable a cell geometry that not only uses 1/100th the material of traditional wafer-based devices, but also may offer increased photovoltaic efficiency owing to an effective optical concentration of up to 20 times.

Original languageEnglish
Pages (from-to)239-244
Number of pages6
JournalNature Materials
Volume9
Issue number3
DOIs
Publication statusPublished - Mar 2010

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wire
Wire
sunlight
Quantum efficiency
quantum efficiency
incidence
wafers
Energy harvesting
Infrared absorption
solar energy
geometrical optics
Solar energy
infrared absorption
Conversion efficiency
unity
Optics
Energy gap
trapping
Semiconductor materials
broadband

ASJC Scopus subject areas

  • Mechanical Engineering
  • Mechanics of Materials
  • Condensed Matter Physics
  • Materials Science(all)
  • Chemistry(all)

Cite this

Kelzenberg, M. D., Boettcher, S. W., Petykiewicz, J. A., Turner-Evans, D. B., Putnam, M. C., Warren, E. L., ... Atwater, H. A. (2010). Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. Nature Materials, 9(3), 239-244. https://doi.org/10.1038/nmat2635

Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. / Kelzenberg, Michael D.; Boettcher, Shannon W.; Petykiewicz, Jan A.; Turner-Evans, Daniel B.; Putnam, Morgan C.; Warren, Emily L.; Spurgeon, Joshua M.; Briggs, Ryan M.; Lewis, Nathan S; Atwater, Harry A.

In: Nature Materials, Vol. 9, No. 3, 03.2010, p. 239-244.

Research output: Contribution to journalArticle

Kelzenberg, MD, Boettcher, SW, Petykiewicz, JA, Turner-Evans, DB, Putnam, MC, Warren, EL, Spurgeon, JM, Briggs, RM, Lewis, NS & Atwater, HA 2010, 'Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications', Nature Materials, vol. 9, no. 3, pp. 239-244. https://doi.org/10.1038/nmat2635
Kelzenberg MD, Boettcher SW, Petykiewicz JA, Turner-Evans DB, Putnam MC, Warren EL et al. Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. Nature Materials. 2010 Mar;9(3):239-244. https://doi.org/10.1038/nmat2635
Kelzenberg, Michael D. ; Boettcher, Shannon W. ; Petykiewicz, Jan A. ; Turner-Evans, Daniel B. ; Putnam, Morgan C. ; Warren, Emily L. ; Spurgeon, Joshua M. ; Briggs, Ryan M. ; Lewis, Nathan S ; Atwater, Harry A. / Enhanced absorption and carrier collection in Si wire arrays for photovoltaic applications. In: Nature Materials. 2010 ; Vol. 9, No. 3. pp. 239-244.
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