The role of oxygen doping on elemental intermixing at the PVD-CdS/Cu (InGa)Se2 heterojunction
Abstract
Elemental intermixing at the CdS/CuIn1-xGaxSe2 (CIGS) heterojunction in thin-film photovoltaic devices plays a crucial role in carrier separation and thus device efficiency. Here, using scanning transmission electron microcopy in combination with energy dispersive X-ray mapping, we find that by controlling the oxygen in the sputtering gas during physical vapor deposition (PVD) of the CdS, we can tailor the degree of elemental intermixing. More oxygen suppresses Cu migration from the CIGS into the CdS, while facilitating Zn doping in the CdS from the ZnO transparent contact. Very high oxygen levels induce nanocrystallinity in the CdS, while moderate or no oxygen content can promote complete CdS epitaxy on the CIGS grains. Regions of cubic Cu2S phase were observed in the Cu-rich CdCuS when no oxygen is included in the CdS deposition process. In the process-of-record sample (moderate O2) that exhibits the highest solar conversion efficiency, we observe a ~26-nm-thick Cu-deficient CIGS surface counter-doped with the highest Cd concentration among all of the samples. Cd movement into the CIGS was found to be less than 10 nm deep for samples with either high or zero O2 . Lastly, the results are consistent with the expectation that Cd doping of the CIGS surface and lackmore »
- Authors:
-
[1];
- University of Illinois at Urbana‐Champaign, Urbana, IL (United States); Univ. of Missouri, Columbia, MO (United States)
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- MiaSolé Hi‐Tech, Santa Clara, CA (United States)
- University of Illinois at Urbana‐Champaign, Urbana, IL (United States); Colorado School of Mines, Golden, CO (United States)
- Publication Date:
- Research Org.:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States)
- Sponsoring Org.:
- USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities Division; USDOE Office of Energy Efficiency and Renewable Energy (EERE)
- OSTI Identifier:
- 1515358
- Alternate Identifier(s):
- OSTI ID: 1506409; OSTI ID: 1786624
- Report Number(s):
- LLNL-JRNL-751864
Journal ID: ISSN 1062-7995; 937854
- Grant/Contract Number:
- AC52-07NA27344; AC02-05CH11231; AC52‐07NA27344; DE‐AC02‐05CH11231
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Progress in Photovoltaics
- Additional Journal Information:
- Journal Volume: 27; Journal Issue: 3; Journal ID: ISSN 1062-7995
- Publisher:
- Wiley
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; CdS structure; Cu (In,Ga)Se2 photovoltaics; Cu diffusion; scanning transmission electron microscopy; STEM‐EDS mapping
Citation Formats
He, Xiaoqing, Ercius, Peter, Varley, Joel B., Bailey, Jeff, Zapalac, Geordie, Nagle, Tim, Poplavskyy, Dmitry, Mackie, Neil, Bayman, Atiye, Lordi, Vincenzo, and Rockett, Angus. The role of oxygen doping on elemental intermixing at the PVD-CdS/Cu (InGa)Se2 heterojunction. United States: N. p., 2018.
Web. doi:10.1002/pip.3087.
He, Xiaoqing, Ercius, Peter, Varley, Joel B., Bailey, Jeff, Zapalac, Geordie, Nagle, Tim, Poplavskyy, Dmitry, Mackie, Neil, Bayman, Atiye, Lordi, Vincenzo, & Rockett, Angus. The role of oxygen doping on elemental intermixing at the PVD-CdS/Cu (InGa)Se2 heterojunction. United States. https://doi.org/10.1002/pip.3087
He, Xiaoqing, Ercius, Peter, Varley, Joel B., Bailey, Jeff, Zapalac, Geordie, Nagle, Tim, Poplavskyy, Dmitry, Mackie, Neil, Bayman, Atiye, Lordi, Vincenzo, and Rockett, Angus. Thu .
"The role of oxygen doping on elemental intermixing at the PVD-CdS/Cu (InGa)Se2 heterojunction". United States. https://doi.org/10.1002/pip.3087. https://www.osti.gov/servlets/purl/1515358.
@article{osti_1515358,
title = {The role of oxygen doping on elemental intermixing at the PVD-CdS/Cu (InGa)Se2 heterojunction},
author = {He, Xiaoqing and Ercius, Peter and Varley, Joel B. and Bailey, Jeff and Zapalac, Geordie and Nagle, Tim and Poplavskyy, Dmitry and Mackie, Neil and Bayman, Atiye and Lordi, Vincenzo and Rockett, Angus},
abstractNote = {Elemental intermixing at the CdS/CuIn1-xGaxSe2 (CIGS) heterojunction in thin-film photovoltaic devices plays a crucial role in carrier separation and thus device efficiency. Here, using scanning transmission electron microcopy in combination with energy dispersive X-ray mapping, we find that by controlling the oxygen in the sputtering gas during physical vapor deposition (PVD) of the CdS, we can tailor the degree of elemental intermixing. More oxygen suppresses Cu migration from the CIGS into the CdS, while facilitating Zn doping in the CdS from the ZnO transparent contact. Very high oxygen levels induce nanocrystallinity in the CdS, while moderate or no oxygen content can promote complete CdS epitaxy on the CIGS grains. Regions of cubic Cu2S phase were observed in the Cu-rich CdCuS when no oxygen is included in the CdS deposition process. In the process-of-record sample (moderate O2) that exhibits the highest solar conversion efficiency, we observe a ~26-nm-thick Cu-deficient CIGS surface counter-doped with the highest Cd concentration among all of the samples. Cd movement into the CIGS was found to be less than 10 nm deep for samples with either high or zero O2 . Lastly, the results are consistent with the expectation that Cd doping of the CIGS surface and lack of Zn diffusion into the buffer both enhance device performance.},
doi = {10.1002/pip.3087},
journal = {Progress in Photovoltaics},
number = 3,
volume = 27,
place = {United States},
year = {Thu Dec 20 00:00:00 EST 2018},
month = {Thu Dec 20 00:00:00 EST 2018}
}
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Works referenced in this record:
Modelling polycrystalline semiconductor solar cells
journal, February 2000
- Burgelman, M.; Nollet, P.; Degrave, S.
- Thin Solid Films, Vol. 361-362
Interface properties and band alignment of Cu2S/CdS thin film solar cells
journal, May 2003
- Liu, Guangming; Schulmeyer, T.; Brötz, J.
- Thin Solid Films, Vol. 431-432
Cd doping at the CuInSe2/CdS heterojunction
journal, June 2003
- Liao, Dongxiang; Rockett, Angus
- Journal of Applied Physics, Vol. 93, Issue 11
New world record efficiency for Cu(In,Ga)Se2 thin-film solar cells beyond 20%
journal, January 2011
- Jackson, Philip; Hariskos, Dimitrios; Lotter, Erwin
- Progress in Photovoltaics: Research and Applications, Vol. 19, Issue 7
Direct evidence of Cd diffusion into Cu(In, Ga)Se2 thin films during chemical-bath deposition process of CdS films
journal, April 1999
- Nakada, T.; Kunioka, A.
- Applied Physics Letters, Vol. 74, Issue 17
The Zn(S,O,OH)/ZnMgO buffer in thin-film Cu(In,Ga)(Se,S) 2 -based solar cells part II: Magnetron sputtering of the ZnMgO buffer layer for in-line co-evaporated Cu(In,Ga)Se 2 solar cells
journal, November 2009
- Hariskos, D.; Fuchs, B.; Menner, R.
- Progress in Photovoltaics: Research and Applications, Vol. 17, Issue 7
Electrical properties of point defects in CdS and ZnS
journal, September 2013
- Varley, J. B.; Lordi, V.
- Applied Physics Letters, Vol. 103, Issue 10
Buffer layers and transparent conducting oxides for chalcopyrite Cu(In,Ga)(S,Se)2 based thin film photovoltaics: present status and current developments
journal, August 2010
- Naghavi, N.; Abou-Ras, D.; Allsop, N.
- Progress in Photovoltaics: Research and Applications, Vol. 18, Issue 6, p. 411-433
CuInSe 2 for photovoltaic applications
journal, October 1991
- Rockett, A.; Birkmire, R. W.
- Journal of Applied Physics, Vol. 70, Issue 7
Prospects for in situ junction formation in CuInSe2 based solar cells
journal, July 1998
- Ramanathan, Kannan; Noufi, Rommel; Granata, Jennifer
- Solar Energy Materials and Solar Cells, Vol. 55, Issue 1-2
High-efficiency Cu(In,Ga)Se2 thin-film solar cells with a CBD-ZnS buffer layer
journal, March 2001
- Nakada, T.; Mizutani, M.; Hagiwara, Y.
- Solar Energy Materials and Solar Cells, Vol. 67, Issue 1-4
Chemical reactions at CdS heterojunctions with CuInSe 2
journal, March 2013
- Aquino, Angel; Rockett, Angus
- Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, Vol. 31, Issue 2
Intermixing at the absorber-buffer layer interface in thin-film solar cells: The electronic effects of point defects in Cu(In,Ga)(Se,S) 2 and Cu 2 ZnSn(Se,S) 4 devices
journal, August 2014
- Varley, J. B.; Lordi, V.
- Journal of Applied Physics, Vol. 116, Issue 6
Photovoltaic Properties of Cu 2 S–CdS Heterojunctions
journal, August 1970
- Gill, W. D.; Bube, R. H.
- Journal of Applied Physics, Vol. 41, Issue 9
The CuInSe2–CuGaSe2–2CdSe system and crystal growth of the γ-solid solutions
journal, August 2010
- Marushko, L. P.; Romanyuk, Y. E.; Piskach, L. V.
- Journal of Alloys and Compounds, Vol. 505, Issue 1
Cd doping at PVD-CdS/CuInGaSe2 heterojunctions
journal, May 2017
- He, Xiaoqing; Paulauskas, Tadas; Ercius, Peter
- Solar Energy Materials and Solar Cells, Vol. 164
Intermixing and Formation of Cu-Rich Secondary Phases at Sputtered CdS/CuInGaSe 2 Heterojunctions
journal, September 2016
- He, Xiaoqing; Varley, Joel; Ercius, Peter
- IEEE Journal of Photovoltaics, Vol. 6, Issue 5
Optimization of CdTe thin-film solar cell efficiency using a sputtered, oxygenated CdS window layer: Optimization of CdTe thin-film solar cell efficiency using a sputtered, oxygenated CdS window layer
journal, January 2015
- Kephart, Jason M.; Geisthardt, Russell M.; Sampath, W. S.
- Progress in Photovoltaics: Research and Applications, Vol. 23, Issue 11
Scripting-customised microscopy tools for Digital Micrograph™
journal, July 2005
- Mitchell, D. R. G.; Schaffer, B.
- Ultramicroscopy, Vol. 103, Issue 4
Solar cell efficiency tables (version 43): Solar cell efficiency tables
journal, December 2013
- Green, Martin A.; Emery, Keith; Hishikawa, Yoshihiro
- Progress in Photovoltaics: Research and Applications, Vol. 22, Issue 1
Microstructural and Chemical Investigation of PVD-CdS/PVD-<inline-formula><tex-math> $\hbox{CuIn}_{\hbox{1-x}} {\hbox{Ga}}_{\hbox{x}} {\hbox{Se}}_{\hbox{2}}$</tex-math></inline-formula> Heterojunctions: A Transmission Electron Microscopy Study
journal, November 2014
- He, X. Q.; Brown, G.; Demirkan, K.
- IEEE Journal of Photovoltaics, Vol. 4, Issue 6
Influence of oxygen concentration in the CdCl 2 treatment process on the photovoltaic properties of CdTe/CdS solar cells
journal, May 2015
- Regalado-Pérez, E.; Reyes-Banda, Martín G.; Mathew, X.
- Thin Solid Films, Vol. 582
Cu depletion at the CuInSe2 surface
journal, April 2003
- Liao, Dongxiang; Rockett, Angus
- Applied Physics Letters, Vol. 82, Issue 17
Structural and chemical investigations of CBD- and PVD-CdS buffer layers and interfaces in Cu(In,Ga)Se2-based thin film solar cells
journal, June 2005
- Abou-Ras, D.; Kostorz, G.; Romeo, A.
- Thin Solid Films, Vol. 480-481
19·9%-efficient ZnO/CdS/CuInGaSe 2 solar cell with 81·2% fill factor
journal, May 2008
- Repins, Ingrid; Contreras, Miguel A.; Egaas, Brian
- Progress in Photovoltaics: Research and Applications, Vol. 16, Issue 3
New Cd-free buffer layer deposited by PVD: In2S3 containing Na compounds
journal, May 2003
- Barreau, N.; Bernède, J. C.; Marsillac, S.
- Thin Solid Films, Vol. 431-432
Properties of reactively sputtered oxygenated cadmium sulfide (CdS:O) and their impact on CdTe solar cell performance
journal, March 2015
- Meysing, Daniel M.; Wolden, Colin A.; Griffith, Michelle M.
- Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, Vol. 33, Issue 2
Reconstruction and energetics of the polar (112) and versus the nonpolar (220) surfaces of
journal, February 2002
- Zhang, S. B.; Wei, S. -H.
- Physical Review B, Vol. 65, Issue 8
Development of thin-film Cu(In,Ga)Se2 and CdTe solar cells
journal, March 2004
- Romeo, A.; Terheggen, M.; Abou-Ras, D.
- Progress in Photovoltaics: Research and Applications, Vol. 12, Issue 23, p. 93-111
Selective Facet Reactivity during Cation Exchange in Cadmium Sulfide Nanorods
journal, April 2009
- Sadtler, Bryce; Demchenko, Denis O.; Zheng, Haimei
- Journal of the American Chemical Society, Vol. 131, Issue 14
Formation of the physical vapor deposited CdS∕Cu(In,Ga)Se2 interface in highly efficient thin film solar cells
journal, April 2006
- Rusu, M.; Glatzel, Th.; Neisser, A.
- Applied Physics Letters, Vol. 88, Issue 14
Optimal and near‐optimal filters in high‐resolution electron microscopy
journal, April 1998
- Kilaas, R.
- Journal of Microscopy, Vol. 190, Issue 1‐2
Exploring Cd-Zn-O-S alloys for improved buffer layers in thin-film photovoltaics
journal, July 2017
- Varley, J. B.; Lordi, V.; He, X.
- Physical Review Materials, Vol. 1, Issue 2
The CdS/Cu2 solar cell
journal, September 1982
- Bo¨er, Karl W.
- Journal of Crystal Growth, Vol. 59, Issue 1-2
Vapor phase treatment of CdTe/CdS thin films with CdCl/sub 2/:O/sub 2/
conference, January 1996
- McCandless, B. E.; Hichri, H.; Hanket, G.
- Conference Record of the Twenty Fifth IEEE Photovoltaic Specialists Conference - 1996
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journal, May 2019
- Han, Jian; Wang, Shuangjie; Li, Xuanhua
- Solar RRL, Vol. 3, Issue 8