Effect of silicon oxide thickness on polysilicon based passivated contacts for high-efficiency crystalline silicon solar cells
Abstract
In this paper, we have investigated the effect of SiOx thickness (1-3 nm) on the performance of polycrystalline (poly) Si/SiOx/monocrystalline Si (c-Si) passivated contacts. Our results show that for both n- and p-type contacts, there is an optimum SiOx thickness of 1.4-1.6 nm for obtaining the highest implied open-circuit voltage (i-Voc) values of ~739 and ~700 mV, respectively. For contacts with SiOx thicker than 1.6 nm, the i-Voc drops due to reduced field-effect passivation. We attribute this to the fact that a thicker SiOx layer hinders the diffusion of both n- and p-type dopants into the c-Si wafer resulting in a junction that is very close to the c-Si/SiOx interface, which increases carrier recombination most likely due to the presence of defects at this interface. The resistivity measured through the metal/poly-Si/SiOx/c-Si stack is independent of SiOx thickness up to 1.6 nm, and increases exponentially by several orders of magnitude with further increase in SiOx thickness due to inefficient tunneling transport. Finally, the extent of metallization-induced degradation of the poly-Si/SiOx/c-Si contacts is worst for the thinnest SiOx investigated (~1 nm), and interestingly it is not completely mitigated even for a ~3 nm thick SiOx.
- Authors:
-
- Colorado School of Mines, Golden, CO (United States)
- National Renewable Energy Lab. (NREL), Golden, CO (United States)
- Publication Date:
- Research Org.:
- National Renewable Energy Laboratory (NREL), Golden, CO (United States)
- Sponsoring Org.:
- USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office
- OSTI Identifier:
- 1461857
- Alternate Identifier(s):
- OSTI ID: 1548168
- Report Number(s):
- NREL/JA-5900-71510
Journal ID: ISSN 0927-0248
- Grant/Contract Number:
- AC36-08GO28308; SETP DE-EE00030301
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Solar Energy Materials and Solar Cells
- Additional Journal Information:
- Journal Volume: 185; Journal Issue: C; Journal ID: ISSN 0927-0248
- Publisher:
- Elsevier
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; silicon solar cell; passivated contact; passivation; silicon oxide; contact resistivity; metallization-induced degradation
Citation Formats
Kale, Abhijit S., Nemeth, William, Harvey, Steven P., Page, Matthew, Young, David L., Agarwal, Sumit, and Stradins, Paul. Effect of silicon oxide thickness on polysilicon based passivated contacts for high-efficiency crystalline silicon solar cells. United States: N. p., 2018.
Web. doi:10.1016/j.solmat.2018.05.011.
Kale, Abhijit S., Nemeth, William, Harvey, Steven P., Page, Matthew, Young, David L., Agarwal, Sumit, & Stradins, Paul. Effect of silicon oxide thickness on polysilicon based passivated contacts for high-efficiency crystalline silicon solar cells. United States. https://doi.org/10.1016/j.solmat.2018.05.011
Kale, Abhijit S., Nemeth, William, Harvey, Steven P., Page, Matthew, Young, David L., Agarwal, Sumit, and Stradins, Paul. Tue .
"Effect of silicon oxide thickness on polysilicon based passivated contacts for high-efficiency crystalline silicon solar cells". United States. https://doi.org/10.1016/j.solmat.2018.05.011. https://www.osti.gov/servlets/purl/1461857.
@article{osti_1461857,
title = {Effect of silicon oxide thickness on polysilicon based passivated contacts for high-efficiency crystalline silicon solar cells},
author = {Kale, Abhijit S. and Nemeth, William and Harvey, Steven P. and Page, Matthew and Young, David L. and Agarwal, Sumit and Stradins, Paul},
abstractNote = {In this paper, we have investigated the effect of SiOx thickness (1-3 nm) on the performance of polycrystalline (poly) Si/SiOx/monocrystalline Si (c-Si) passivated contacts. Our results show that for both n- and p-type contacts, there is an optimum SiOx thickness of 1.4-1.6 nm for obtaining the highest implied open-circuit voltage (i-Voc) values of ~739 and ~700 mV, respectively. For contacts with SiOx thicker than 1.6 nm, the i-Voc drops due to reduced field-effect passivation. We attribute this to the fact that a thicker SiOx layer hinders the diffusion of both n- and p-type dopants into the c-Si wafer resulting in a junction that is very close to the c-Si/SiOx interface, which increases carrier recombination most likely due to the presence of defects at this interface. The resistivity measured through the metal/poly-Si/SiOx/c-Si stack is independent of SiOx thickness up to 1.6 nm, and increases exponentially by several orders of magnitude with further increase in SiOx thickness due to inefficient tunneling transport. Finally, the extent of metallization-induced degradation of the poly-Si/SiOx/c-Si contacts is worst for the thinnest SiOx investigated (~1 nm), and interestingly it is not completely mitigated even for a ~3 nm thick SiOx.},
doi = {10.1016/j.solmat.2018.05.011},
journal = {Solar Energy Materials and Solar Cells},
number = C,
volume = 185,
place = {United States},
year = {Tue May 29 00:00:00 EDT 2018},
month = {Tue May 29 00:00:00 EDT 2018}
}
Web of Science
Figures / Tables:
Works referenced in this record:
Interdigitated back contact solar cells with polycrystalline silicon on oxide passivating contacts for both polarities
journal, July 2017
- Haase, Felix; Kiefer, Fabian; Schäfer, Sören
- Japanese Journal of Applied Physics, Vol. 56, Issue 8S2
n-Type Si solar cells with passivating electron contact: Identifying sources for efficiency limitations by wafer thickness and resistivity variation
journal, December 2017
- Richter, Armin; Benick, Jan; Feldmann, Frank
- Solar Energy Materials and Solar Cells, Vol. 173
Low temperature Si/SiOx /pc-Si passivated contacts to n-type Si solar cells
conference, June 2014
- Nemeth, Bill; Young, David L.; Yuan, Hao-Chih
- 2014 IEEE 40th Photovoltaic Specialists Conference (PVSC), 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)
Efficient carrier-selective p- and n-contacts for Si solar cells
journal, December 2014
- Feldmann, Frank; Simon, Maik; Bivour, Martin
- Solar Energy Materials and Solar Cells, Vol. 131
IBC c-Si solar cells based on ion-implanted poly-silicon passivating contacts
journal, December 2016
- Yang, Guangtao; Ingenito, Andrea; Isabella, Olindo
- Solar Energy Materials and Solar Cells, Vol. 158
Ultrathin (<4 nm) SiO2 and Si–O–N gate dielectric layers for silicon microelectronics: Understanding the processing, structure, and physical and electrical limits
journal, September 2001
- Green, M. L.; Gusev, E. P.; Degraeve, R.
- Journal of Applied Physics, Vol. 90, Issue 5
The SIS tunnel emitter: A theory for emitters with thin interface layers
journal, November 1979
- de Graaff, H. C.; de Groot, J. G.
- IEEE Transactions on Electron Devices, Vol. 26, Issue 11
Understanding the limits of ultrathin SiO2 and SiON gate dielectrics for sub-50 nm CMOS
journal, September 1999
- Green, M. L.; Sorsch, T. W.; Timp, G. L.
- Microelectronic Engineering, Vol. 48, Issue 1-4
Pinhole density and contact resistivity of carrier selective junctions with polycrystalline silicon on oxide
journal, June 2017
- Wietler, T. F.; Tetzlaff, D.; Krügener, J.
- Applied Physics Letters, Vol. 110, Issue 25
High-eficiency silicon solar cells: Si/SiO2, interface parameters and their impact on device performance
journal, October 1994
- Aberle, A. G.; Glunz, S. W.; Stephens, A. W.
- Progress in Photovoltaics: Research and Applications, Vol. 2, Issue 4
Surface passivation of crystalline silicon solar cells: a review
journal, January 2000
- Aberle, Armin G.
- Progress in Photovoltaics: Research and Applications, Vol. 8, Issue 5, p. 473-487
Heavily doped polysilicon-contact solar cells
journal, July 1985
- Lindholm, F. A.; Neugroschel, A.; Arienzo, M.
- IEEE Electron Device Letters, Vol. 6, Issue 7
A 720 mV open circuit voltage SiO x : c ‐Si:SiO x double heterostructure solar cell
journal, December 1985
- Yablonovitch, E.; Gmitter, T.; Swanson, R. M.
- Applied Physics Letters, Vol. 47, Issue 11
Polycrystalline silicon passivated tunneling contacts for high efficiency silicon solar cells
journal, March 2016
- Nemeth, Bill; Young, David L.; Page, Matthew R.
- Journal of Materials Research, Vol. 31, Issue 6, p. 671-681
Tunnel oxide passivated carrier-selective contacts based on ultra-thin SiO 2 layers
journal, November 2015
- Moldovan, Anamaria; Feldmann, Frank; Zimmer, Martin
- Solar Energy Materials and Solar Cells, Vol. 142
Recombination behavior and contact resistance of n+ and p+ poly-crystalline Si/mono-crystalline Si junctions
journal, December 2014
- Römer, Udo; Peibst, Robby; Ohrdes, Tobias
- Solar Energy Materials and Solar Cells, Vol. 131
Passivating electron contact based on highly crystalline nanostructured silicon oxide layers for silicon solar cells
journal, December 2016
- Stuckelberger, Josua; Nogay, Gizem; Wyss, Philippe
- Solar Energy Materials and Solar Cells, Vol. 158
Structure and morphology of polycrystalline silicon‐single crystal silicon interfaces
journal, April 1985
- Bravman, John C.; Patton, Gary L.; Plummer, James D.
- Journal of Applied Physics, Vol. 57, Issue 8
An investigation of the thermal stability of the interfacial oxide in polycrystalline silicon emitter bipolar transistors by comparing device results with high‐resolution electron microscopy observations
journal, January 1987
- Wolstenholme, G. R.; Jorgensen, N.; Ashburn, P.
- Journal of Applied Physics, Vol. 61, Issue 1
Quasi-steady-state photoconductance, a new method for solar cell material and device characterization
conference, January 1996
- Sinton, R. A.; Cuevas, A.; Stuckings, M.
- Conference Record of the Twenty Fifth IEEE Photovoltaic Specialists Conference - 1996
Photoluminescence imaging for determining the spatially resolved implied open circuit voltage of silicon solar cells
journal, January 2014
- Hallam, Brett; Tjahjono, Budi; Trupke, Thorsten
- Journal of Applied Physics, Vol. 115, Issue 4
Carrier-selective, passivated contacts for high efficiency silicon solar cells based on transparent conducting oxides
conference, June 2014
- Young, David L.; Nemeth, William; Grover, Sachit
- 2014 IEEE 40th Photovoltaic Specialists Conference (PVSC), 2014 IEEE 40th Photovoltaic Specialist Conference (PVSC)
The application of poly-Si/SiOx contacts as passivated top/rear contacts in Si solar cells
journal, January 2017
- Feldmann, Frank; Reichel, Christian; Müller, Ralph
- Solar Energy Materials and Solar Cells, Vol. 159
Recent advances of high-efficiency single crystalline silicon solar cells in processing technologies and substrate materials
journal, May 2004
- Zhao, J.
- Solar Energy Materials and Solar Cells, Vol. 82, Issue 1-2
Metallization for Very-Large-Scale Integrated Circuits
journal, January 1981
- Ghate, P. B.
- MRS Proceedings, Vol. 10
Works referencing / citing this record:
Understanding the charge transport mechanisms through ultrathin SiO x layers in passivated contacts for high-efficiency silicon solar cells
journal, February 2019
- Kale, Abhijit S.; Nemeth, William; Guthrey, Harvey
- Applied Physics Letters, Vol. 114, Issue 8
Metal-induced gap states in passivating metal/silicon contacts
journal, February 2019
- Sajjad, Muhammad; Yang, Xinbo; Altermatt, Pietro
- Applied Physics Letters, Vol. 114, Issue 7
Figures / Tables found in this record: