Search Menu
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information
Search Scholarly Publications

Title: High-efficiency selective boron emitter formed by wet chemical etch-back for n-type screen-printed Si solar cells

Abstract

Front metal contact induced recombination and resistance are major efficiency limiting factors of large-area screen-printed n-type front junction Si solar cells with homogeneous emitter and tunnel oxide passivated back contact (TOPCON). Here, this paper shows the development of a selective boron emitter (p+/p++) formed by a screen-printed resist masking and wet chemical etch-back process, which first grows a porous Si layer and subsequently removes it. Various wet-chemical solutions for forming porous Si layer are investigated. An industrial compatible process with sodium nitrite (NaNO2) catalyst is developed to uniformly etch-back the ~47 Ω/ atmospheric pressure chemical vapor deposited heavily doped boron emitter to ~135 Ω/ by growing a 320 nm porous Si layer within 3 min and subsequently removing it. After etching back, the boron emitter was subjected to a thermal oxidation to lower the surface concentration and the emitter saturation current density J0e. Various etched-back emitters were evaluated by measuring J0e on symmetric test structures with atomic layer deposited aluminum oxide (Al2O3) passivation. Very low J0e of 21, 14, and 9 fA/cm2 were obtained for the 120, 150, and 180 Ω/ etched-back emitters, respectively. A solar cell with a selective emitter (65/180 Ω/ ) formed by this etch-back technology andmore » with an Al/Ag contact on the front and TOPCON on the back gave an open-circuit voltage (Voc) of 682.8 mV and efficiency of 21.04% on n-type Czochralski Si wafer. Finally, this demonstrates the potential of this technology for next generation high-efficiency industrial n-type Si solar cells.« less

Authors:
ORCiD logo [1];  [1];  [1];  [1];  [1];  [2]
+ Show Author Affiliations
  1. Georgia Inst. of Technology, Atlanta, GA (United States)
  2. Georgia Inst. of Technology, Atlanta, GA (United States); Suniva Inc., Norcross, GA (United States)
Publication Date:
Research Org.:
Georgia Institute of Technology, Atlanta, GA (United States); Suniva, Inc., Norcross, GA (United States)
Sponsoring Org.:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
OSTI Identifier:
1465957
Alternate Identifier(s):
OSTI ID: 1361726; OSTI ID: 1893848; OSTI ID: 1893911
Grant/Contract Number:  
EE0006336; EE0006815; EE0007554
Resource Type:
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 110; Journal Issue: 2; Journal ID: ISSN 0003-6951
Publisher:
American Institute of Physics (AIP)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 14 SOLAR ENERGY; Semiconductor device fabrication; Solar cells; Electrical properties and parameters; Electric measurements; Chemical elements; Catalysts and Catalysis; Chemical solutions; Microfabrication; Etching

Citation Formats

Tao, Yuguo, Madani, Keeya, Cho, Eunhwan, Rounsaville, Brian, Upadhyaya, Vijaykumar, and Rohatgi, Ajeet. High-efficiency selective boron emitter formed by wet chemical etch-back for n-type screen-printed Si solar cells. United States: N. p., 2017. Web. doi:10.1063/1.4973626.
Copy to clipboard
Tao, Yuguo, Madani, Keeya, Cho, Eunhwan, Rounsaville, Brian, Upadhyaya, Vijaykumar, & Rohatgi, Ajeet. High-efficiency selective boron emitter formed by wet chemical etch-back for n-type screen-printed Si solar cells. United States. https://doi.org/10.1063/1.4973626
Copy to clipboard
Tao, Yuguo, Madani, Keeya, Cho, Eunhwan, Rounsaville, Brian, Upadhyaya, Vijaykumar, and Rohatgi, Ajeet. Mon . "High-efficiency selective boron emitter formed by wet chemical etch-back for n-type screen-printed Si solar cells". United States. https://doi.org/10.1063/1.4973626. https://www.osti.gov/servlets/purl/1465957.
Copy to clipboard
@article{osti_1465957,
title = {High-efficiency selective boron emitter formed by wet chemical etch-back for n-type screen-printed Si solar cells},
author = {Tao, Yuguo and Madani, Keeya and Cho, Eunhwan and Rounsaville, Brian and Upadhyaya, Vijaykumar and Rohatgi, Ajeet},
abstractNote = {Front metal contact induced recombination and resistance are major efficiency limiting factors of large-area screen-printed n-type front junction Si solar cells with homogeneous emitter and tunnel oxide passivated back contact (TOPCON). Here, this paper shows the development of a selective boron emitter (p+/p++) formed by a screen-printed resist masking and wet chemical etch-back process, which first grows a porous Si layer and subsequently removes it. Various wet-chemical solutions for forming porous Si layer are investigated. An industrial compatible process with sodium nitrite (NaNO2) catalyst is developed to uniformly etch-back the ~47 Ω/ atmospheric pressure chemical vapor deposited heavily doped boron emitter to ~135 Ω/ by growing a 320 nm porous Si layer within 3 min and subsequently removing it. After etching back, the boron emitter was subjected to a thermal oxidation to lower the surface concentration and the emitter saturation current density J0e. Various etched-back emitters were evaluated by measuring J0e on symmetric test structures with atomic layer deposited aluminum oxide (Al2O3) passivation. Very low J0e of 21, 14, and 9 fA/cm2 were obtained for the 120, 150, and 180 Ω/ etched-back emitters, respectively. A solar cell with a selective emitter (65/180 Ω/ ) formed by this etch-back technology and with an Al/Ag contact on the front and TOPCON on the back gave an open-circuit voltage (Voc) of 682.8 mV and efficiency of 21.04% on n-type Czochralski Si wafer. Finally, this demonstrates the potential of this technology for next generation high-efficiency industrial n-type Si solar cells.},
doi = {10.1063/1.4973626},
journal = {Applied Physics Letters},
number = 2,
volume = 110,
place = {United States},
year = {Mon Jan 09 00:00:00 EST 2017},
month = {Mon Jan 09 00:00:00 EST 2017}
}
Copy to clipboard
Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
https://doi.org/10.1063/1.4973626
Copyright Statement
Other availability
Search WorldCat Search WorldCat to find libraries that may hold this journal
Citation Metrics:
Cited by: 39 works
Citation information provided by
Web of Science
Save / Share:
Export Metadata
Save to My Library
You must Sign In or Create an Account in order to save documents to your library.

Works referenced in this record:

Achievement of More Than 25% Conversion Efficiency With Crystalline Silicon Heterojunction Solar Cell
journal, November 2014

Effects of Stain Etchant Composition on the Photoluminescence and Morphology of Porous Silicon
journal, January 2006

  • Nahidi, Mona; Kolasinski, Kurt W.
  • Journal of The Electrochemical Society, Vol. 153, Issue 1
  • DOI: 10.1149/1.2129558

Passivated rear contacts for high-efficiency n-type Si solar cells providing high interface passivation quality and excellent transport characteristics
journal, January 2014

High efficiency chemical etchant for the formation of luminescent porous silicon
journal, March 1994

  • Kelly, Michael T.; Chun, Jonathan K. M.; Bocarsly, Andrew B.
  • Applied Physics Letters, Vol. 64, Issue 13
  • DOI: 10.1063/1.111834

Fully Ion-Implanted and Screen-Printed 20.2% Efficient Front Junction Silicon Cells on 239 cm $^{\bf 2}$ n-Type CZ Substrate
journal, January 2014

Silicon nanostructures from electroless electrochemical etching
journal, February 2005

Recombination activity of interstitial iron and other transition metal point defects in p- and n-type crystalline silicon
journal, November 2004

  • Macdonald, Daniel; Geerligs, L. J.
  • Applied Physics Letters, Vol. 85, Issue 18
  • DOI: 10.1063/1.1812833

Reassessment of the intrinsic carrier density in crystalline silicon in view of band-gap narrowing
journal, February 2003

  • Altermatt, Pietro P.; Schenk, Andreas; Geelhaar, Frank
  • Journal of Applied Physics, Vol. 93, Issue 3
  • DOI: 10.1063/1.1529297

Chemical etching of silicon: Smooth, rough, and glowing surfaces
journal, December 1995

General parameterization of Auger recombination in crystalline silicon
journal, February 2002

  • Kerr, Mark J.; Cuevas, Andres
  • Journal of Applied Physics, Vol. 91, Issue 4
  • DOI: 10.1063/1.1432476

Large area tunnel oxide passivated rear contact n -type Si solar cells with 21.2% efficiency : Large area tunnel oxide passivated rear contact
journal, January 2016

  • Tao, Yuguo; Upadhyaya, Vijaykumar; Chen, Chia-Wei
  • Progress in Photovoltaics: Research and Applications, Vol. 24, Issue 6
  • DOI: 10.1002/pip.2739

Minority carrier lifetime degradation in boron-doped Czochralski silicon
journal, September 2001

  • Glunz, S. W.; Rein, S.; Lee, J. Y.
  • Journal of Applied Physics, Vol. 90, Issue 5
  • DOI: 10.1063/1.1389076

Photoluminescence imaging of silicon wafers
journal, July 2006

  • Trupke, T.; Bardos, R. A.; Schubert, M. C.
  • Applied Physics Letters, Vol. 89, Issue 4
  • DOI: 10.1063/1.2234747

On the Mechanism of Chemically Etching Germanium and Silicon
journal, January 1960

  • Turner, D. R.
  • Journal of The Electrochemical Society, Vol. 107, Issue 10
  • DOI: 10.1149/1.2427519

Co-diffusion from APCVD BSG and POCl3 for Industrial n-type Solar Cells
journal, January 2013

Modeling the potential of screen printed front junction CZ silicon solar cell with tunnel oxide passivated back contact: Screen printed TOPCon front junction Cz Si solar cell
journal, October 2016

  • Chen, Chia-Wei; Hermle, Martin; Benick, Jan
  • Progress in Photovoltaics: Research and Applications, Vol. 25, Issue 1
  • DOI: 10.1002/pip.2809

Carrier-selective contacts for Si solar cells
journal, May 2014

  • Feldmann, F.; Simon, M.; Bivour, M.
  • Applied Physics Letters, Vol. 104, Issue 18
  • DOI: 10.1063/1.4875904
    Sort by:
    [ × clear filter / sort ]

    Similar Records in DOE PAGES and OSTI.GOV collections: