Emitter Choice for Epitaxial CdTe Solar Cells

doi:https://doi.org/10.1109/PVSC.2016.7749971

Title: Emitter Choice for Epitaxial CdTe Solar Cells

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Abstract

High-quality epitaxial CdTe layers with low defect density and high carrier concentration have been demonstrated by several research groups. Nevertheless, one primary challenge for high-performance epitaxial CdTe solar cells is how to choose a suitable emitter partner for the junction formation. The numerical simulations show that a type I heterojunction with small conduction band offset (0.1 eV = ..delta..Ec = 0.3 eV) is necessary to maintain a good cell efficiency even with large interface recombination. Otherwise, a small 'cliff' can assist interface recombination causing smaller Voc, and a large 'spike' (..delta..Ec = 0.4 eV) can impede the photo current and lead to a reduction of JSC and FF. Among the three possible emitters, CdS, CdMgTe, and MgZnO, CdMgTe (with ~30% Mg) and MgZnO (with ~ 20% Mg) are likely to be a better choice since their type-I junction can tolerate a larger density of interface defects.

Authors:: Song, Tao; Kanevce, Ana; Sites, James R.

Publication Date:: 2016-11-21

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), SunShot Initiative

OSTI Identifier:: 1344214

Report Number(s):: NREL/CP-5K00-67984

DOE Contract Number:: AC36-08GO28308

Resource Type:: Conference

Resource Relation:: Conference: Presented at the 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC), 5-10 June 2016, Portland, Oregon

Country of Publication:: United States

Language:: English

Subject:: 14 SOLAR ENERGY; 36 MATERIALS SCIENCE; solar cells; emitter; heterojunction; CdTe

Citation Formats


                    Song, Tao, Kanevce, Ana, and Sites, James R. Emitter Choice for Epitaxial CdTe Solar Cells.  United States: N. p., 2016. 
        Web.  doi:10.1109/PVSC.2016.7749971.

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                    Song, Tao, Kanevce, Ana, & Sites, James R. Emitter Choice for Epitaxial CdTe Solar Cells.  United States.  https://doi.org/10.1109/PVSC.2016.7749971

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                    Song, Tao, Kanevce, Ana, and Sites, James R. Mon .  
        "Emitter Choice for Epitaxial CdTe Solar Cells".  United States.  https://doi.org/10.1109/PVSC.2016.7749971.

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@article{osti_1344214,

  title        = {Emitter Choice for Epitaxial CdTe Solar Cells},

  author       = {Song, Tao and Kanevce, Ana and Sites, James R.},

  abstractNote = {High-quality epitaxial CdTe layers with low defect density and high carrier concentration have been demonstrated by several research groups. Nevertheless, one primary challenge for high-performance epitaxial CdTe solar cells is how to choose a suitable emitter partner for the junction formation. The numerical simulations show that a type I heterojunction with small conduction band offset (0.1 eV = ..delta..Ec = 0.3 eV) is necessary to maintain a good cell efficiency even with large interface recombination. Otherwise, a small 'cliff' can assist interface recombination causing smaller Voc, and a large 'spike' (..delta..Ec = 0.4 eV) can impede the photo current and lead to a reduction of JSC and FF. Among the three possible emitters, CdS, CdMgTe, and MgZnO, CdMgTe (with ~30% Mg) and MgZnO (with ~ 20% Mg) are likely to be a better choice since their type-I junction can tolerate a larger density of interface defects.},

  doi          = {10.1109/PVSC.2016.7749971},

  url          = {https://www.osti.gov/biblio/1344214},
  journal      = {},
number       = ,

  volume       = ,

  place        = {United States},

  year         = {2016},

  month        = {11}

}

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