Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies

Tunnel Oxide Passivated Contact (TOPCon) cell performance relies significantly on hydrogen for its passivation of defects. In this paper, we discuss the temperature dependent effusion of hydrogen from the silicon nitride (SixNy) layers deposited on top of poly-Si/SiO2 passivated contacts. Silicon c...

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Main Authors: Suchismita Mitra, Dirk Steyn, William Nemeth, Sumit Agarwal, Paul Stradins
Format: Article
Language:English
Published: TIB Open Publishing 2025-01-01
Series:SiliconPV Conference Proceedings
Subjects:
Online Access:https://www.tib-op.org/ojs/index.php/siliconpv/article/view/1312
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author Suchismita Mitra
Dirk Steyn
William Nemeth
Sumit Agarwal
Paul Stradins
author_facet Suchismita Mitra
Dirk Steyn
William Nemeth
Sumit Agarwal
Paul Stradins
author_sort Suchismita Mitra
collection DOAJ
description Tunnel Oxide Passivated Contact (TOPCon) cell performance relies significantly on hydrogen for its passivation of defects. In this paper, we discuss the temperature dependent effusion of hydrogen from the silicon nitride (SixNy) layers deposited on top of poly-Si/SiO2 passivated contacts. Silicon content in SixNywas varied by silane/ammonia flow ratio. FTIR shows significant N-H stretching & bending peaks for nitrogen-rich SixNy layer compared to silicon-rich SixNy layer, and few Si-H bonds compared to silicon-rich SixNy. During effusion, the N-H bonds in N-rich SixNy layer break to provide H2 , NH3 and N2, resulting in stoichiometry change. Negligible effusion of nitrogen occurs for Si-rich SixNylayers. Next, we investigate the mechanism of hydrogen passivation on symmetrical i-poly-Si/SiO2/i-poly-Si structures with different hydrogenating layers namely Si-rich SixNy , Al2O3 and a stack of Al2O3/SixNy, and conclude that a thin 15nm Al2O3 enables the best passivation. We also discuss the possibility of H diffusion in molecular H2 form, most suitable for SiO2 interface passivation, while the atomic hydrogen enables both passivation and de-passivation of interface dangling bonds.
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spelling doaj-art-cda6600b9d82461c899af5d1759ab0662025-01-10T09:49:18ZengTIB Open PublishingSiliconPV Conference Proceedings2940-21232025-01-01210.52825/siliconpv.v2i.1312Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies Suchismita Mitra0https://orcid.org/0000-0001-5747-0327Dirk Steyn1https://orcid.org/0000-0001-5146-3820William Nemeth2Sumit Agarwal3https://orcid.org/0000-0002-4453-3656Paul Stradins4https://orcid.org/0000-0002-3073-5564National Renewable Energy LaboratoryColorado School of MinesNational Renewable Energy LaboratoryColorado School of MinesNational Renewable Energy Laboratory Tunnel Oxide Passivated Contact (TOPCon) cell performance relies significantly on hydrogen for its passivation of defects. In this paper, we discuss the temperature dependent effusion of hydrogen from the silicon nitride (SixNy) layers deposited on top of poly-Si/SiO2 passivated contacts. Silicon content in SixNywas varied by silane/ammonia flow ratio. FTIR shows significant N-H stretching & bending peaks for nitrogen-rich SixNy layer compared to silicon-rich SixNy layer, and few Si-H bonds compared to silicon-rich SixNy. During effusion, the N-H bonds in N-rich SixNy layer break to provide H2 , NH3 and N2, resulting in stoichiometry change. Negligible effusion of nitrogen occurs for Si-rich SixNylayers. Next, we investigate the mechanism of hydrogen passivation on symmetrical i-poly-Si/SiO2/i-poly-Si structures with different hydrogenating layers namely Si-rich SixNy , Al2O3 and a stack of Al2O3/SixNy, and conclude that a thin 15nm Al2O3 enables the best passivation. We also discuss the possibility of H diffusion in molecular H2 form, most suitable for SiO2 interface passivation, while the atomic hydrogen enables both passivation and de-passivation of interface dangling bonds. https://www.tib-op.org/ojs/index.php/siliconpv/article/view/1312TOPCON CellsHydrogen EffusionDefect PassivationSilicon Nitride LayersAluminium Oxide Layers
spellingShingle Suchismita Mitra
Dirk Steyn
William Nemeth
Sumit Agarwal
Paul Stradins
Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
SiliconPV Conference Proceedings
TOPCON Cells
Hydrogen Effusion
Defect Passivation
Silicon Nitride Layers
Aluminium Oxide Layers
title Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
title_full Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
title_fullStr Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
title_full_unstemmed Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
title_short Understanding Hydrogen Passivation Mechanism in poly-Si Passivating Contacts via SixNy Composition: Insights From Effusion Studies
title_sort understanding hydrogen passivation mechanism in poly si passivating contacts via sixny composition insights from effusion studies
topic TOPCON Cells
Hydrogen Effusion
Defect Passivation
Silicon Nitride Layers
Aluminium Oxide Layers
url https://www.tib-op.org/ojs/index.php/siliconpv/article/view/1312
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AT sumitagarwal understandinghydrogenpassivationmechanisminpolysipassivatingcontactsviasixnycompositioninsightsfromeffusionstudies
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