DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Mesoscale trumps nanoscale: metallic mesoscale contact morphology for improved light trapping, optical absorption and grid conductance in silicon solar cells

Abstract

Here, we report on a computational study exploring the design of mesoscale metallic front contacts for solar cells. We investigated silver contact structures with circle, triangle and square cross-sections for various length scales and surface coverages. We found that for ‘nanoscale’ contacts with widths between 10 nm and 1000 nm, resonant coupling actually impairs light absorption in the semiconductor. Conversely, for ‘mesoscale’ contact widths > 1000 nm, the light interaction is determined by the geometric shadowing. We find that mesoscale silver contacts with triangular cross-section outperform other nanostructure morphologies in reducing shadow losses and yield contact transparency of >99% percent with sheet resistance <0.2 Ω/sq. Surprisingly, very densely spaced mesoscale silver triangular cross-section contacts can enhance the absorption of thin silicon/silver structures by up to 15% at a front contact coverage of 83%, due to light trapping by the front contact. Such structures can also maintain up to 100% absorption within the silicon, at a front contact coverage of 50%, relative to the same structure without metal.

Authors:
ORCiD logo; ORCiD logo
Publication Date:
Research Org.:
The Leland Stanford Junior Univ., Palo Alto, CA (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE)
OSTI Identifier:
1423923
Alternate Identifier(s):
OSTI ID: 1503310
Grant/Contract Number:  
EE0004946; EEC-1041895
Resource Type:
Published Article
Journal Name:
Optics Express
Additional Journal Information:
Journal Name: Optics Express Journal Volume: 26 Journal Issue: 6; Journal ID: ISSN 1094-4087
Publisher:
Optical Society of America
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; 36 MATERIALS SCIENCE; Solar energy; Micro-optics; Nanophotonics and photonic crystals

Citation Formats

Saive, Rebecca, and Atwater, Harry A. Mesoscale trumps nanoscale: metallic mesoscale contact morphology for improved light trapping, optical absorption and grid conductance in silicon solar cells. United States: N. p., 2018. Web. doi:10.1364/OE.26.00A275.
Saive, Rebecca, & Atwater, Harry A. Mesoscale trumps nanoscale: metallic mesoscale contact morphology for improved light trapping, optical absorption and grid conductance in silicon solar cells. United States. https://doi.org/10.1364/OE.26.00A275
Saive, Rebecca, and Atwater, Harry A. Tue . "Mesoscale trumps nanoscale: metallic mesoscale contact morphology for improved light trapping, optical absorption and grid conductance in silicon solar cells". United States. https://doi.org/10.1364/OE.26.00A275.
@article{osti_1423923,
title = {Mesoscale trumps nanoscale: metallic mesoscale contact morphology for improved light trapping, optical absorption and grid conductance in silicon solar cells},
author = {Saive, Rebecca and Atwater, Harry A.},
abstractNote = {Here, we report on a computational study exploring the design of mesoscale metallic front contacts for solar cells. We investigated silver contact structures with circle, triangle and square cross-sections for various length scales and surface coverages. We found that for ‘nanoscale’ contacts with widths between 10 nm and 1000 nm, resonant coupling actually impairs light absorption in the semiconductor. Conversely, for ‘mesoscale’ contact widths > 1000 nm, the light interaction is determined by the geometric shadowing. We find that mesoscale silver contacts with triangular cross-section outperform other nanostructure morphologies in reducing shadow losses and yield contact transparency of >99% percent with sheet resistance <0.2 Ω/sq. Surprisingly, very densely spaced mesoscale silver triangular cross-section contacts can enhance the absorption of thin silicon/silver structures by up to 15% at a front contact coverage of 83%, due to light trapping by the front contact. Such structures can also maintain up to 100% absorption within the silicon, at a front contact coverage of 50%, relative to the same structure without metal.},
doi = {10.1364/OE.26.00A275},
journal = {Optics Express},
number = 6,
volume = 26,
place = {United States},
year = {2018},
month = {3}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1364/OE.26.00A275

Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

Figures / Tables:

Fig. 1 Fig. 1: Schematic of the interaction of light with wave vector and metal structures of width w in the a) nanoscale (w<<λ), b) mesoscale (w ≥ λ) and c) macroscale (w>>λ).

Save / Share:

Works referenced in this record:

Double Printing nPERT Cells with Narrow Contact Layers
journal, August 2016


Transparent Conducting Silver Nanowire Networks
journal, May 2012

  • van de Groep, Jorik; Spinelli, Pierpaolo; Polman, Albert
  • Nano Letters, Vol. 12, Issue 6
  • DOI: 10.1021/nl301045a

24.7% Record Efficiency HIT Solar Cell on Thin Silicon Wafer
journal, January 2014


Scaling effect on specific contact resistivity in nano-scale metal-semiconductor contacts
conference, June 2013

  • Park, S. -H.; Kharche, N.; Basu, D.
  • 2013 71st Annual Device Research Conference (DRC), 71st Device Research Conference
  • DOI: 10.1109/drc.2013.6633825

Solar Cell Improvement by using a Multi Busbar Design as Front Electrode
journal, January 2012


Optical Design of Textured Thin-Film CIGS Solar Cells with Nearly-Invisible Nanowire Assisted Front Contacts
journal, April 2017

  • Deelen, Joop; Omar, Ahmed; Barink, Marco
  • Materials, Vol. 10, Issue 4
  • DOI: 10.3390/ma10040392

High aspect ratio electrodeposited Ni/Au contacts for GaAs-based III-V concentrator solar cells: Electrodeposited Ni/Au contacts for GaAs based concentrator solar cells
journal, March 2014

  • Ward, J. Scott; Duda, Anna; Friedman, Daniel J.
  • Progress in Photovoltaics: Research and Applications, Vol. 23, Issue 5
  • DOI: 10.1002/pip.2490

Self-consistent optical parameters of intrinsic silicon at 300K including temperature coefficients
journal, November 2008


Obtaining the specific contact resistance from transmission line model measurements
journal, May 1982


Shading losses of solar‐cell metal grids
journal, May 1992

  • Blakers, A. W.
  • Journal of Applied Physics, Vol. 71, Issue 10
  • DOI: 10.1063/1.350580

Analysis of an anti-reflecting nanowire transparent electrode for solar cells
journal, March 2017

  • Zhao, Zhexin; Wang, Ken Xingze; Fan, Shanhui
  • Journal of Applied Physics, Vol. 121, Issue 11
  • DOI: 10.1063/1.4978769

Enhancing the optical transmittance by using circular silver nanowire networks
journal, May 2014

  • Xie, Shouyi; Ouyang, Zi; Stokes, Nicholas
  • Journal of Applied Physics, Vol. 115, Issue 19
  • DOI: 10.1063/1.4876676

Transparent Electrodes for Efficient Optoelectronics
journal, March 2017

  • Morales-Masis, Monica; De Wolf, Stefaan; Woods-Robinson, Rachel
  • Advanced Electronic Materials, Vol. 3, Issue 5
  • DOI: 10.1002/aelm.201600529

Cloaked contact grids on solar cells by coordinate transformations: designs and prototypes
journal, January 2015

  • Schumann, Martin F.; Wiesendanger, Samuel; Goldschmidt, Jan Christoph
  • Optica, Vol. 2, Issue 10
  • DOI: 10.1364/optica.2.000850

Performance enhancement of metal nanowire transparent conducting electrodes by mesoscale metal wires
journal, September 2013

  • Hsu, Po-Chun; Wang, Shuang; Wu, Hui
  • Nature Communications, Vol. 4, Issue 1
  • DOI: 10.1038/ncomms3522

Effectively Transparent Front Contacts for Optoelectronic Devices
journal, June 2016

  • Saive, Rebecca; Borsuk, Aleca M.; Emmer, Hal S.
  • Advanced Optical Materials, Vol. 4, Issue 10
  • DOI: 10.1002/adom.201600252

Hybrid Metal–Semiconductor Nanostructure for Ultrahigh Optical Absorption and Low Electrical Resistance at Optoelectronic Interfaces
journal, October 2015


Silicon heterojunction solar cells with effectively transparent front contacts
journal, January 2017

  • Saive, Rebecca; Boccard, Mathieu; Saenz, Theresa
  • Sustainable Energy & Fuels, Vol. 1, Issue 3
  • DOI: 10.1039/c7se00096k

Catoptric electrodes: transparent metal electrodes using shaped surfaces
journal, January 2014


The role of propagating modes in silver nanowire arrays for transparent electrodes
journal, January 2013


Cloaked contact grids on solar cells by coordinate transformations: designs and prototypes
journal, January 2015

  • Schumann, Martin F.; Wiesendanger, Samuel; Goldschmidt, Jan Christoph
  • Optica, Vol. 2, Issue 10
  • DOI: 10.1364/OPTICA.2.000850

Catoptric electrodes: transparent metal electrodes using shaped surfaces
journal, January 2014


Silicon heterojunction solar cells with effectively transparent front contacts
journal, January 2017

  • Saive, Rebecca; Boccard, Mathieu; Saenz, Theresa
  • Sustainable Energy & Fuels, Vol. 1, Issue 3
  • DOI: 10.1039/C7SE00096K

The role of propagating modes in silver nanowire arrays for transparent electrodes
journal, January 2013


24.7% Record Efficiency HIT Solar Cell on Thin Silicon Wafer
journal, January 2014


Obtaining the specific contact resistance from transmission line model measurements
journal, May 1982


Scaling effect on specific contact resistivity in nano-scale metal-semiconductor contacts
conference, June 2013

  • Park, S. -H.; Kharche, N.; Basu, D.
  • 2013 71st Annual Device Research Conference (DRC), 71st Device Research Conference
  • DOI: 10.1109/DRC.2013.6633825

Works referencing / citing this record:

Evolutionary design algorithm for optimal light trapping in solar cells
journal, January 2019

  • Gouvêa, Rogério Almeida; Moreira, Mário Lúcio; Souza, Jeferson Avila
  • Journal of Applied Physics, Vol. 125, Issue 4
  • DOI: 10.1063/1.5078745

Figures/Tables have been extracted from DOE-funded journal article accepted manuscripts.