TY - JOUR

T1 - Changes in hydrogen concentration and defect state density at the poly-Si/SiOx/c-Si interface due to firing

AU - Hollemann, Christina

AU - Folchert, Nils

AU - Harvey, Steven P.

AU - Stradins, Paul

AU - Young, David L.

AU - Salles de Souza, Caroline Lima

AU - Rienäcker, Michael

AU - Haase, Felix

AU - Brendel, Rolf

AU - Peibst, Robby

N1 - Funding Information: The authors thank the Federal Ministry for Economic Affairs and Energy (BMWi) and the state of Lower Saxony for funding this work, Hilke Fischer, Annika Raugewitz, Anja Christ (all from ISFH), Raymond Zieseniss and Guido Glowatzki (both from the Institute of Electronic Materials and Devices) for sample processing and Martin Rudolf and Henning Schulte-Huxel for the FTIR measurement. This work was authored in part by the National Renewable Energy Laboratory, operated by Alliance for Sustainable Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding provided by the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Solar Energy Technologies Office. The views expressed in the article do not necessarily represent the views of the DOE or the U.S. Government. The U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow others to do so, for U.S. Government purposes.

PY - 2021/10

Y1 - 2021/10

N2 - We determined the density of defect states of poly-Si/SiOx/c-Si junctions featuring a wet chemical interfacial oxide from lifetime measurements using the MarcoPOLO model to calculate recombination and contact resistance in poly-Si/SiOx/c-Si-junctions. In samples that did not receive any hydrogen treatment, the Dit,cSi is about 2 × 1012 cm−2 eV⁻1 before firing and rises to 3–7 × 1012 cm⁻2 eV⁻1 during firing at measured peak temperatures between 620 °C and 863 °C. To address the question of why AlOx/SiNy stacks in contrast to pure SiNy layers for hydrogenation during firing provides better passivation quality, we have measured the hydrogen concentrations at the poly-Si/SiOx/c-Si interface as a function of AlOx layer thickness and compared these to J0 and calculated Dit,c-Si values. We observe an increase of the hydrogen concentration at the SiOx/c-Si interface upon firing as a function of the firing temperature that exceeds the defect concentrations at the interface several times. However, the AlOx layer thickness appears to cause an increase in hydrogen concentration at the SiOx/c-Si interface in these samples rather than exhibiting a hydrogen blocking property.

AB - We determined the density of defect states of poly-Si/SiOx/c-Si junctions featuring a wet chemical interfacial oxide from lifetime measurements using the MarcoPOLO model to calculate recombination and contact resistance in poly-Si/SiOx/c-Si-junctions. In samples that did not receive any hydrogen treatment, the Dit,cSi is about 2 × 1012 cm−2 eV⁻1 before firing and rises to 3–7 × 1012 cm⁻2 eV⁻1 during firing at measured peak temperatures between 620 °C and 863 °C. To address the question of why AlOx/SiNy stacks in contrast to pure SiNy layers for hydrogenation during firing provides better passivation quality, we have measured the hydrogen concentrations at the poly-Si/SiOx/c-Si interface as a function of AlOx layer thickness and compared these to J0 and calculated Dit,c-Si values. We observe an increase of the hydrogen concentration at the SiOx/c-Si interface upon firing as a function of the firing temperature that exceeds the defect concentrations at the interface several times. However, the AlOx layer thickness appears to cause an increase in hydrogen concentration at the SiOx/c-Si interface in these samples rather than exhibiting a hydrogen blocking property.

KW - Firing

KW - Hydrogen

KW - MarcoPOLO

KW - Modeling

KW - Passivating contacts

KW - POLO

UR - http://www.scopus.com/inward/record.url?scp=85111545101&partnerID=8YFLogxK

U2 - 10.1016/j.solmat.2021.111297

DO - 10.1016/j.solmat.2021.111297

M3 - Article

AN - SCOPUS:85111545101

VL - 231

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

SN - 0927-0248

M1 - 111297

ER -