Towards 28 %-efficient Si single-junction solar cells with better passivating POLO junctions and photonic crystals

verfasst von: R. Peibst, M. Rienäcker, Y. Larionova, N. Folchert, F. Haase, C. Hollemann, S. Wolter, J. Krügener, P. Bayerl, J. Bayer, M. Dzinnik, R. J. Haug, R. Brendel
Abstract: We conduct numerical device simulations to study to what extend poly-Si on oxide (POLO)² IBC solar cells can be optimized. In particular, we evaluate the benefit of the concept of photonic crystals (PCs) for “standard” cell thicknesses compatible with industrial wafer handling. We find that for our current surface passivation quality, implementing PCs and decreasing the wafer thickness down to 15 μm would increase the efficiency by „only“ 1% absolute due to limiting surface recombination losses. We deduce a high c-Si/SiO_x interface state density D_it of 2.9 × 10¹² eV⁻¹cm⁻² by analyzing special two-terminal IV measurements on small pads that contact the intact interfacial oxide between pinholes with our MarcoPOLO model. Consequently, we improve the hydrogenation process of our POLO junctions by an Al₂O₃/SiN_x/Al₂O₃ rear-side dielectric layer stack. For n-type POLO (p-type POLO) J₀ is reduced from 4 (10) fA/cm² down to 0.5 ± 0.3 (3.3 ± 0.7) fA/cm². For this improved surface passivation, our numerical device simulations predict an efficiency potential of 29.1% (27.8%) for POLO² IBC cells with (without) PCs for a standard thickness of 150 μm. This shows that the “practical limit” for Si solar cells with poly-Si on oxide-based passivating contact schemes is above 27%, and, in general, that the efficiency potential of Si single-junction cells is still far from being exhausted. The first implementation of the improved POLO junctions into cell precursors confirms the predicted improvement on the level of suns - implied open-circuit voltage curves.
Organisationseinheit(en): Institut für Materialien und Bauelemente der Elektronik
Institut für Festkörperphysik
Abt. Nanostrukturen
Laboratorium für Nano- und Quantenengineering
Abt. Solarenergie
QuantumFrontiers
Externe Organisation(en): Institut für Solarenergieforschung GmbH (ISFH)
Typ: Artikel
Journal: Solar Energy Materials and Solar Cells
Band: 238
ISSN: 0927-0248
Publikationsdatum: 05.2022
Publikationsstatus: Veröffentlicht
Peer-reviewed: Ja
ASJC Scopus Sachgebiete: Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Oberflächen, Beschichtungen und Folien
Ziele für nachhaltige Entwicklung: SDG 7 – Erschwingliche und saubere Energie
Elektronische Version(en): https://doi.org/10.1016/j.solmat.2021.111560 (Zugang: Geschlossen)

BibTeX

@article{3e279acfce944a4c9c19ccc3248bf886,
title = "Towards 28 %-efficient Si single-junction solar cells with better passivating POLO junctions and photonic crystals",
abstract = "We conduct numerical device simulations to study to what extend poly-Si on oxide (POLO)2 IBC solar cells can be optimized. In particular, we evaluate the benefit of the concept of photonic crystals (PCs) for “standard” cell thicknesses compatible with industrial wafer handling. We find that for our current surface passivation quality, implementing PCs and decreasing the wafer thickness down to 15 μm would increase the efficiency by „only“ 1% absolute due to limiting surface recombination losses. We deduce a high c-Si/SiOx interface state density Dit of 2.9 × 1012 eV−1cm−2 by analyzing special two-terminal IV measurements on small pads that contact the intact interfacial oxide between pinholes with our MarcoPOLO model. Consequently, we improve the hydrogenation process of our POLO junctions by an Al2O3/SiNx/Al2O3 rear-side dielectric layer stack. For n-type POLO (p-type POLO) J0 is reduced from 4 (10) fA/cm2 down to 0.5 ± 0.3 (3.3 ± 0.7) fA/cm2. For this improved surface passivation, our numerical device simulations predict an efficiency potential of 29.1% (27.8%) for POLO2 IBC cells with (without) PCs for a standard thickness of 150 μm. This shows that the “practical limit” for Si solar cells with poly-Si on oxide-based passivating contact schemes is above 27%, and, in general, that the efficiency potential of Si single-junction cells is still far from being exhausted. The first implementation of the improved POLO junctions into cell precursors confirms the predicted improvement on the level of suns - implied open-circuit voltage curves.",
author = "R. Peibst and M. Rien{\"a}cker and Y. Larionova and N. Folchert and F. Haase and C. Hollemann and S. Wolter and J. Kr{\"u}gener and P. Bayerl and J. Bayer and M. Dzinnik and Haug, {R. J.} and R. Brendel",
note = "Funding Information: We would like to thank H. Fischer, S. Sp{\"a}tlich, R. Winter, A. Raugewitz,G. Glowatzki and R. Zieseniβ for sample processing, M. Wolf, A. Dietrich, R. Reineke-Koch for discussion and support with the measurement systems, and Sajeev John for fruitful discussions. This work is funded by the German Ministry for Economic Affairs and Energy (grant FKZ 003EE1056A ), by the federal state of Lower Saxony and by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany's Excellence Strategy - EXC-2123 QuantumFrontiers – 390837967. ",
year = "2022",
month = may,
doi = "10.1016/j.solmat.2021.111560",
language = "English",
volume = "238",
journal = "Solar Energy Materials and Solar Cells",
issn = "0927-0248",
publisher = "Elsevier BV",
}