Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells

doi:10.1063/1.4921416

Title: Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells

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Abstract

This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta{sub 2}O{sub 5}) underneath plasma enhanced chemical vapour deposited silicon nitride (SiN{sub x}). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta{sub 2}O{sub 5} and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm{sup 2} and 68 fA/cm{sup 2} are measured on 150 Ω/sq boron-diffused p{sup +} and 120 Ω/sq phosphorus-diffused n{sup +} c-Si, respectively. Capacitance–voltage measurements reveal a negative fixed insulator charge density of −1.8 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5} film and −1.0 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5}/SiN{sub x} stack. The Ta{sub 2}O{sub 5}/SiN{sub x} stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells.

Authors:

Wan, Yimao, E-mail: yimao.wan@anu.edu.au; Bullock, James; Cuevas, Andres ^[1]

Research School of Engineering, The Australian National University, Canberra, ACT 0200 (Australia)

Publication Date:: 2015-05-18

OSTI Identifier:: 22402449

Resource Type:: Journal Article

Journal Name:: Applied Physics Letters

Additional Journal Information:: Journal Volume: 106; Journal Issue: 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0003-6951

Country of Publication:: United States

Language:: English

Subject:: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; BORON; CHARGE DENSITY; CHEMICAL VAPOR DEPOSITION; CURRENT DENSITY; DOPED MATERIALS; FILMS; LAYERS; PASSIVATION; PHOSPHORUS; RECOMBINATION; SILICON; SILICON NITRIDES; SILICON SOLAR CELLS; SURFACES; TANTALUM OXIDES; TRANSMISSION ELECTRON MICROSCOPY

Citation Formats


                    Wan, Yimao, E-mail: yimao.wan@anu.edu.au, Bullock, James, and Cuevas, Andres. Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells.  United States: N. p., 2015. 
        Web.  doi:10.1063/1.4921416.

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                    Wan, Yimao, E-mail: yimao.wan@anu.edu.au, Bullock, James, & Cuevas, Andres. Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells.  United States.  doi:10.1063/1.4921416.

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                    Wan, Yimao, E-mail: yimao.wan@anu.edu.au, Bullock, James, and Cuevas, Andres. Mon .  
        "Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells".  United States.  doi:10.1063/1.4921416.

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@article{osti_22402449,

  title        = {Tantalum oxide/silicon nitride: A negatively charged surface passivation stack for silicon solar cells},

  author       = {Wan, Yimao, E-mail: yimao.wan@anu.edu.au and Bullock, James and Cuevas, Andres},

  abstractNote = {This letter reports effective passivation of crystalline silicon (c-Si) surfaces by thermal atomic layer deposited tantalum oxide (Ta{sub 2}O{sub 5}) underneath plasma enhanced chemical vapour deposited silicon nitride (SiN{sub x}). Cross-sectional transmission electron microscopy imaging shows an approximately 2 nm thick interfacial layer between Ta{sub 2}O{sub 5} and c-Si. Surface recombination velocities as low as 5.0 cm/s and 3.2 cm/s are attained on p-type 0.8 Ω·cm and n-type 1.0 Ω·cm c-Si wafers, respectively. Recombination current densities of 25 fA/cm{sup 2} and 68 fA/cm{sup 2} are measured on 150 Ω/sq boron-diffused p{sup +} and 120 Ω/sq phosphorus-diffused n{sup +} c-Si, respectively. Capacitance–voltage measurements reveal a negative fixed insulator charge density of −1.8 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5} film and −1.0 × 10{sup 12 }cm{sup −2} for the Ta{sub 2}O{sub 5}/SiN{sub x} stack. The Ta{sub 2}O{sub 5}/SiN{sub x} stack is demonstrated to be an excellent candidate for surface passivation of high efficiency silicon solar cells.},

  doi          = {10.1063/1.4921416},

  journal      = {Applied Physics Letters},

  issn         = {0003-6951},

  number       = 20,

  volume       = 106,

  place        = {United States},

  year         = {2015},

  month        = {5}

}

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DOI: 10.1063/1.4921416

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