Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement

doi:10.1016/j.solmat.2017.07.006

Title: Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement

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Abstract

Introducing K into Cu(In,Ga)(Se,S) ₂ (CIGS) absorbers has led to recent world record power conversion efficiencies for thin film polycrystalline solar cells. In this work, the diverse phenomena associated with K in CIGS were reviewed, and overarching mechanisms were identified. The effects of K depend on its distribution among grain interiors (GIs), grain boundaries (GBs), and interfaces. High substrate Na and low temperature favor GI K incorporation, while low Na and high temperature favor segregation of K at GBs. Depositing KInSe ₂ (or KIn _1-yGaySe ₂) by co-evaporation or KF post-deposition treatment onto CIGS reduces buffer interface recombination in the final solar cells. KInSe ₂ decomposes in air, which makes characterization difficult and may affect performance. In conclusion, the mechanism for reduced interface recombination could be direct passivation, beneficial compound precursor, oxidation barrier, or favorable diffusion alteration.

Authors:

Muzzillo, Christopher P. ^[1]

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

Publication Date:: 2017-07-16

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

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

OSTI Identifier:: 1373683

Alternate Identifier(s):: OSTI ID: 1549569

Report Number(s):: NREL/JA-5K00-68981
Journal ID: ISSN 0927-0248

Grant/Contract Number:: AC36-08GO28308

Resource Type:: Journal Article: Accepted Manuscript

Journal Name:: Solar Energy Materials and Solar Cells

Additional Journal Information:: Journal Volume: 172; Journal Issue: C; Journal ID: ISSN 0927-0248

Publisher:: Elsevier

Country of Publication:: United States

Language:: English

Subject:: 14 SOLAR ENERGY; chalcopyrite; Cu(In,Ga)Se2; potassium; alkali metal; KInSe2; K(In,Ga)Se2

Citation Formats


                    Muzzillo, Christopher P. Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement.  United States: N. p., 2017. 
        Web.  doi:10.1016/j.solmat.2017.07.006.

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                    Muzzillo, Christopher P. Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement.  United States.  doi:10.1016/j.solmat.2017.07.006.

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                    Muzzillo, Christopher P. Sun .  
        "Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement".  United States.  doi:10.1016/j.solmat.2017.07.006.  https://www.osti.gov/servlets/purl/1373683.

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@article{osti_1373683,

  title        = {Review of grain interior, grain boundary, and interface effects of K in CIGS solar cells: Mechanisms for performance enhancement},

  author       = {Muzzillo, Christopher P.},

  abstractNote = {Introducing K into Cu(In,Ga)(Se,S)2 (CIGS) absorbers has led to recent world record power conversion efficiencies for thin film polycrystalline solar cells. In this work, the diverse phenomena associated with K in CIGS were reviewed, and overarching mechanisms were identified. The effects of K depend on its distribution among grain interiors (GIs), grain boundaries (GBs), and interfaces. High substrate Na and low temperature favor GI K incorporation, while low Na and high temperature favor segregation of K at GBs. Depositing KInSe2 (or KIn1-yGaySe2) by co-evaporation or KF post-deposition treatment onto CIGS reduces buffer interface recombination in the final solar cells. KInSe2 decomposes in air, which makes characterization difficult and may affect performance. In conclusion, the mechanism for reduced interface recombination could be direct passivation, beneficial compound precursor, oxidation barrier, or favorable diffusion alteration.},

  doi          = {10.1016/j.solmat.2017.07.006},

  journal      = {Solar Energy Materials and Solar Cells},

  issn         = {0927-0248},

  number       = C,

  volume       = 172,

  place        = {United States},

  year         = {2017},

  month        = {7}

}

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DOI: 10.1016/j.solmat.2017.07.006

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