Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells

Jain, Aditi; Choi, Wook-Jin; Huang, Ying-Yuan; Klein, Benjamin; Rohatgi, Ajeet

doi:10.1109/jphotov.2021.3086461

Title: Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells

Abstract

In this article, detailed numerical modeling is performed for front junction (FJ) and rear junction (RJ) n-type Si solar cells with screen-printed double-side poly-Si based tunnel oxide passivated contacts (TOPCon). A roadmap for efficiency projections of commercial-type RJ and FJ topologies reaching 24.8% and 23.3% efficiencies, respectively, has been developed to quantify and explain the impact of various technological innovations on the performance of each design. Understanding of mechanisms governing cell operation is crucial to explore factors that limit the efficiency potential of the two device structures. By investigating several key parameters such as front poly-Si sheet resistance and thickness, bulk material properties, and current transport in our simulation model, we determine and explain why RJ cells outperform FJ cells. Furthermore, our findings reveal that FJ suffers from present technological limitations of p-type poly-Si based passivated contacts-namely, 1) large recombination observed in textured p-TOPCon layers and 2) low boron solid solubility and hole mobility in boron-doped poly-Si which results in very high sheet resistance of the front p-poly-Si emitter that contributes to fill factor degradation, especially when using thin poly-Si layer to reduce absorption losses. RJ on the contrary desensitizes the cell efficiency to front sheet resistance to allow themore »« less

Authors:

^[1]; Choi, Wook-Jin ^[1];

^[1]; Klein, Benjamin ^[2];

^[1]

Georgia Institute of Technology, Atlanta, GA (United States)
Kennesaw State Univ., Marietta, GA (United States)

Publication Date:: Wed Jun 23 00:00:00 EDT 2021

Research Org.:: Georgia Institute of Technology, Atlanta, GA (United States)

Sponsoring Org.:: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Renewable Power Office. Solar Energy Technologies Office

OSTI Identifier:: 1895325

Alternate Identifier(s):: OSTI ID: 2282743

Grant/Contract Number:: EE0008562; EE0009350

Resource Type:: Accepted Manuscript

Journal Name:: IEEE Journal of Photovoltaics

Additional Journal Information:: Journal Volume: 11; Journal Issue: 5; Journal ID: ISSN 2156-3381

Publisher:: IEEE

Country of Publication:: United States

Language:: English

Subject:: 14 SOLAR ENERGY; double-side topcon; front junction; passivated contacts; rear junction; roadmap; screen-printed contacts; passivated contacts, double-side TOPCon, screen-printed contacts, front junction, rear junction, roadmap

Citation Formats


                    Jain, Aditi, Choi, Wook-Jin, Huang, Ying-Yuan, Klein, Benjamin, and Rohatgi, Ajeet. Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells.  United States: N. p., 2021. 
Web.  doi:10.1109/jphotov.2021.3086461.

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                    Jain, Aditi, Choi, Wook-Jin, Huang, Ying-Yuan, Klein, Benjamin, & Rohatgi, Ajeet. Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells.  United States.  https://doi.org/10.1109/jphotov.2021.3086461

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                    Jain, Aditi, Choi, Wook-Jin, Huang, Ying-Yuan, Klein, Benjamin, and Rohatgi, Ajeet. Wed .  
"Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells".  United States.  https://doi.org/10.1109/jphotov.2021.3086461.  https://www.osti.gov/servlets/purl/1895325.

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@article{osti_1895325,

  title        = {Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells},

  author       = {Jain, Aditi and Choi, Wook-Jin and Huang, Ying-Yuan and Klein, Benjamin and Rohatgi, Ajeet},

  abstractNote = {In this article, detailed numerical modeling is performed for front junction (FJ) and rear junction (RJ) n-type Si solar cells with screen-printed double-side poly-Si based tunnel oxide passivated contacts (TOPCon). A roadmap for efficiency projections of commercial-type RJ and FJ topologies reaching 24.8% and 23.3% efficiencies, respectively, has been developed to quantify and explain the impact of various technological innovations on the performance of each design. Understanding of mechanisms governing cell operation is crucial to explore factors that limit the efficiency potential of the two device structures. By investigating several key parameters such as front poly-Si sheet resistance and thickness, bulk material properties, and current transport in our simulation model, we determine and explain why RJ cells outperform FJ cells. Furthermore, our findings reveal that FJ suffers from present technological limitations of p-type poly-Si based passivated contacts-namely, 1) large recombination observed in textured p-TOPCon layers and 2) low boron solid solubility and hole mobility in boron-doped poly-Si which results in very high sheet resistance of the front p-poly-Si emitter that contributes to fill factor degradation, especially when using thin poly-Si layer to reduce absorption losses. RJ on the contrary desensitizes the cell efficiency to front sheet resistance to allow the application of ultra-thin front n-type poly-Si layer and is therefore ideally suited for double-side TOPCon cells.},

  doi          = {10.1109/jphotov.2021.3086461},

  journal      = {IEEE Journal of Photovoltaics},

  number       = 5,

  volume       = 11,

  place        = {United States},

  year         = {Wed Jun 23 00:00:00 EDT 2021},

  month        = {Wed Jun 23 00:00:00 EDT 2021}

}

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Title: Design, Optimization, and In-Depth Understanding of Front and Rear Junction Double-Side Passivated Contacts Solar Cells

Abstract

Citation Formats

Study of screen printed metallization for polysilicon based passivating contacts journal, September 2017

Parasitic Absorption in Polycrystalline Si-layers for Carrier-selective Front Junctions journal, August 2016

A Free and Fast Three-Dimensional/Two-Dimensional Solar Cell Simulator Featuring Conductive Boundary and Quasi-Neutrality Approximations journal, February 2013

Full wafer size IBC cell with polysilicon passivating contacts conference, January 2018

Metallisation of Boron-Doped Polysilicon Layers by Screen Printed Silver Pastes journal, October 2017

Screen printed, large area bifacial N-type back junction silicon solar cells with selective phosphorus front surface field and boron doped poly-Si/SiO x passivated rear emitter journal, December 2018

OPAL 2: Rapid optical simulation of silicon solar cells conference, June 2012

Ultra‐Thin Poly‐Si Layers: Passivation Quality, Utilization of Charge Carriers Generated in the Poly‐Si and Application on Screen‐Printed Double‐Side Contacted Polycrystalline Si on Oxide Cells journal, August 2020

Double-sided TOPCon solar cells on textured wafer with ALD SiOx layer journal, April 2020

Development of thin polysilicon layers for application in monoPoly™ cells with screen-printed and fired metallization journal, April 2020

Multi-wire Interconnection of Busbar-free Solar Cells journal, January 2014

Carrier-selective contacts for Si solar cells journal, May 2014

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Characteristics of Polycrystalline Si Thin Film—Solid Solubility and Mobility Study journal, September 2015

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The application of poly-Si/SiOx contacts as passivated top/rear contacts in Si solar cells journal, January 2017

Optical properties of phosphorus‐doped polycrystalline silicon layers journal, November 1981

PolySi Based Passivating Contacts Enabling Industrial Silicon Solar Cell Efficiencies up to 24% conference, June 2019

Study of screen printed metallization for polysilicon based passivating contacts
journal, September 2017

Parasitic Absorption in Polycrystalline Si-layers for Carrier-selective Front Junctions
journal, August 2016

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journal, February 2013

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conference, January 2018

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journal, October 2017

Screen printed, large area bifacial N-type back junction silicon solar cells with selective phosphorus front surface field and boron doped poly-Si/SiO _x passivated rear emitter
journal, December 2018

OPAL 2: Rapid optical simulation of silicon solar cells
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Ultra‐Thin Poly‐Si Layers: Passivation Quality, Utilization of Charge Carriers Generated in the Poly‐Si and Application on Screen‐Printed Double‐Side Contacted Polycrystalline Si on Oxide Cells
journal, August 2020

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