Low-Cd CIGS solar cells made with a hybrid CdS/Zn(O,S) buffer layer

Garris, Rebekah L.; Mansfield, Lorelle M.; Egaas, Brian; Ramanathan, Kannan

doi:10.1109/JPHOTOV.2016.2617041

Title: Low-Cd CIGS solar cells made with a hybrid CdS/Zn(O,S) buffer layer

Abstract

In Cu(In,Ga)Se2 (CIGS) solar cells, CdS and Zn(O,S) buffer layers were compared with a hybrid buffer layer consisting of thin CdS followed Zn(O,S). We explore the physics of this hybrid layer that combines the standard (Cd) approach with the alternative (Zn) approach in the pursuit to unlock further potential for CIGS technology. CdS buffer development has shown optimal interface properties, whereas Zn(O,S) buffer development has shown increased photocurrent. Although a totally Cd-free solar module is more marketable, the retention of a small amount of Cd can be beneficial to achieve optimum junction properties. As long as the amount of Cd is reduced to less than 0.01% by weight, the presence of Cd does not violate the hazardous substance restrictions of the European Union (EU). We estimate the amount of Cd allowed in the EU for CIGS on both glass and stainless steel substrates, and we show that reducing Cd becomes increasingly important as substrate weights decrease. As a result, this hybrid buffer layer had reduced Cd content and a wider space charge region, while achieving equal or better solar cell performance than buffer layers of either CdS or Zn(O,S) alone.

Authors:

Garris, Rebekah L. ^[1]; Mansfield, Lorelle M. ^[1]; Egaas, Brian ^[1]; Ramanathan, Kannan ^[1]

National Renewable Energy Lab. (NREL), Golden, CO (United States)

Publication Date:: Thu Oct 27 00:00:00 EDT 2016

Research Org.:: National Renewable Energy Lab. (NREL), Golden, CO (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE)

OSTI Identifier:: 1357746

Report Number(s):: NREL/JA-5K00-66614
Journal ID: ISSN 2156-3381

Grant/Contract Number:: AC36-08GO28308

Resource Type:: Journal Article: Accepted Manuscript

Journal Name:: IEEE Journal of Photovoltaics

Additional Journal Information:: Journal Volume: 7; Journal Issue: 1; Journal ID: ISSN 2156-3381

Publisher:: IEEE

Country of Publication:: United States

Language:: English

Subject:: 14 SOLAR ENERGY; alternative buffer layer; Cd-free; CdS; Cu(In,Ga)Se2 (CIGS); low-Cd; thin-film photovoltaic; Zn(O,S)

Citation Formats


                    Garris, Rebekah L., Mansfield, Lorelle M., Egaas, Brian, and Ramanathan, Kannan. Low-Cd CIGS solar cells made with a hybrid CdS/Zn(O,S) buffer layer.  United States: N. p., 2016. 
        Web.  doi:10.1109/JPHOTOV.2016.2617041.

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                    Garris, Rebekah L., Mansfield, Lorelle M., Egaas, Brian, & Ramanathan, Kannan. Low-Cd CIGS solar cells made with a hybrid CdS/Zn(O,S) buffer layer.  United States.  https://doi.org/10.1109/JPHOTOV.2016.2617041

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                    Garris, Rebekah L., Mansfield, Lorelle M., Egaas, Brian, and Ramanathan, Kannan. 2016.  
        "Low-Cd CIGS solar cells made with a hybrid CdS/Zn(O,S) buffer layer".  United States.  https://doi.org/10.1109/JPHOTOV.2016.2617041.  https://www.osti.gov/servlets/purl/1357746.

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@article{osti_1357746,

  title        = {Low-Cd CIGS solar cells made with a hybrid CdS/Zn(O,S) buffer layer},

  author       = {Garris, Rebekah L. and Mansfield, Lorelle M. and Egaas, Brian and Ramanathan, Kannan},

  abstractNote = {In Cu(In,Ga)Se2 (CIGS) solar cells, CdS and Zn(O,S) buffer layers were compared with a hybrid buffer layer consisting of thin CdS followed Zn(O,S). We explore the physics of this hybrid layer that combines the standard (Cd) approach with the alternative (Zn) approach in the pursuit to unlock further potential for CIGS technology. CdS buffer development has shown optimal interface properties, whereas Zn(O,S) buffer development has shown increased photocurrent. Although a totally Cd-free solar module is more marketable, the retention of a small amount of Cd can be beneficial to achieve optimum junction properties. As long as the amount of Cd is reduced to less than 0.01% by weight, the presence of Cd does not violate the hazardous substance restrictions of the European Union (EU). We estimate the amount of Cd allowed in the EU for CIGS on both glass and stainless steel substrates, and we show that reducing Cd becomes increasingly important as substrate weights decrease. As a result, this hybrid buffer layer had reduced Cd content and a wider space charge region, while achieving equal or better solar cell performance than buffer layers of either CdS or Zn(O,S) alone.},

  doi          = {10.1109/JPHOTOV.2016.2617041},

  url          = {https://www.osti.gov/biblio/1357746},
  journal      = {IEEE Journal of Photovoltaics},

  issn         = {2156-3381},

  number       = 1,

  volume       = 7,

  place        = {United States},

  year         = {Thu Oct 27 00:00:00 EDT 2016},

  month        = {Thu Oct 27 00:00:00 EDT 2016}

}

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https://doi.org/10.1109/JPHOTOV.2016.2617041

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Works referencing / citing this record:

Large metastability in Cu (In,Ga)Se 2 devices: The importance of buffer properties
journal, June 2019

Repins, Ingrid; Glynn, Stephen; Silverman, Timothy J.
Progress in Photovoltaics: Research and Applications, Vol. 27, Issue 9
https://doi.org/10.1002/pip.3145

Pure phase synthesis of Cu ₃ PS ₄ and Cu ₆ PS ₅ Cl for semiconductor applications
journal, January 2018

Graeser, Brian; Agrawal, Rakesh
RSC Advances, Vol. 8, Issue 59
https://doi.org/10.1039/c8ra06241b

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