Potential-Induced Degradation of Cu(In,Ga)Se2 Solar Cells: Alkali Metal Drift and Diffusion Effects

doi:https://doi.org/10.1109/JPHOTOV.2018.2858549

Title: Potential-Induced Degradation of Cu(In,Ga)Se ₂ Solar Cells: Alkali Metal Drift and Diffusion Effects

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Abstract

Potential-induced degradation (PID) of photovoltaic modules is due to transport of alkali metal ions (Na ⁺) from the soda-lime glass (SLG) into the semiconductors. For the most efficient polycrystalline absorbers, Na and K in the Cu(In,Ga)(Se,S) ₂ (CIGS) absorber often benefit performance, so a more detailed mechanism for PID is needed. To that end, CIGS solar cells have been encapsulated, stressed with high voltage, and cored to extract the active regions for characterization. SLG substrates led to 14.9% efficiency on average, which reduced to 0% after 25 h of -1000 V bias. This was accompanied by increased Na in the CIGS layer, particularly at the buffer interface, as well as decreased carrier concentrations. On the other hand, borosilicate glass substrates with low Na and high K content led to 13.6% efficiency on average, which only reduced to 12.1% after 25 h of stress. This was accompanied by slightly increased K content in the CIGS layer. As K has led to recent world record efficiency CIGS devices, understanding Na and K similarities and differences may help to enhance initial efficiency and reduce PID.

Authors:

^[1]; Glynn, Stephen ^[1];

^[1]; Moutinho, Helio R. ^[1]; Young, Matthew R. ^[1]; Teeter, Glenn ^[1];

^[1];

^[1]

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

Publication Date:: 2018-08-06

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

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)

OSTI Identifier:: 1466561

Report Number(s):: NREL/JA-5K00-71604
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: 8; Journal Issue: 5; Journal ID: ISSN 2156-3381

Publisher:: IEEE

Country of Publication:: United States

Language:: English

Subject:: 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; alkali metal; Cu(In,Ga)(Se,S)2 (CIGS); potassium; encapsulation; potential-induced degradation (PID); sodium

Citation Formats


                    Muzzillo, Christopher P., Glynn, Stephen, Hacke, Peter, Moutinho, Helio R., Young, Matthew R., Teeter, Glenn, Repins, Ingrid L., and Mansfield, Lorelle M. Potential-Induced Degradation of Cu(In,Ga)Se2 Solar Cells: Alkali Metal Drift and Diffusion Effects.  United States: N. p., 2018. 
        Web.  doi:10.1109/JPHOTOV.2018.2858549.

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                    Muzzillo, Christopher P., Glynn, Stephen, Hacke, Peter, Moutinho, Helio R., Young, Matthew R., Teeter, Glenn, Repins, Ingrid L., & Mansfield, Lorelle M. Potential-Induced Degradation of Cu(In,Ga)Se2 Solar Cells: Alkali Metal Drift and Diffusion Effects.  United States.  https://doi.org/10.1109/JPHOTOV.2018.2858549

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                    Muzzillo, Christopher P., Glynn, Stephen, Hacke, Peter, Moutinho, Helio R., Young, Matthew R., Teeter, Glenn, Repins, Ingrid L., and Mansfield, Lorelle M. Mon .  
        "Potential-Induced Degradation of Cu(In,Ga)Se2 Solar Cells: Alkali Metal Drift and Diffusion Effects".  United States.  https://doi.org/10.1109/JPHOTOV.2018.2858549.  https://www.osti.gov/servlets/purl/1466561.

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@article{osti_1466561,

  title        = {Potential-Induced Degradation of Cu(In,Ga)Se2 Solar Cells: Alkali Metal Drift and Diffusion Effects},

  author       = {Muzzillo, Christopher P. and Glynn, Stephen and Hacke, Peter and Moutinho, Helio R. and Young, Matthew R. and Teeter, Glenn and Repins, Ingrid L. and Mansfield, Lorelle M.},

  abstractNote = {Potential-induced degradation (PID) of photovoltaic modules is due to transport of alkali metal ions (Na+) from the soda-lime glass (SLG) into the semiconductors. For the most efficient polycrystalline absorbers, Na and K in the Cu(In,Ga)(Se,S)2 (CIGS) absorber often benefit performance, so a more detailed mechanism for PID is needed. To that end, CIGS solar cells have been encapsulated, stressed with high voltage, and cored to extract the active regions for characterization. SLG substrates led to 14.9% efficiency on average, which reduced to 0% after 25 h of -1000 V bias. This was accompanied by increased Na in the CIGS layer, particularly at the buffer interface, as well as decreased carrier concentrations. On the other hand, borosilicate glass substrates with low Na and high K content led to 13.6% efficiency on average, which only reduced to 12.1% after 25 h of stress. This was accompanied by slightly increased K content in the CIGS layer. As K has led to recent world record efficiency CIGS devices, understanding Na and K similarities and differences may help to enhance initial efficiency and reduce PID.},

  doi          = {10.1109/JPHOTOV.2018.2858549},

  url          = {https://www.osti.gov/biblio/1466561},
  journal      = {IEEE Journal of Photovoltaics},

  issn         = {2156-3381},

  number       = 5,

  volume       = 8,

  place        = {United States},

  year         = {2018},

  month        = {8}

}

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Title: Potential-Induced Degradation of Cu(In,Ga)Se 2 Solar Cells: Alkali Metal Drift and Diffusion Effects

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Citation Formats

Title: Potential-Induced Degradation of Cu(In,Ga)Se ₂ Solar Cells: Alkali Metal Drift and Diffusion Effects