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The science behind Quokka3

Quokka's models are documented in the peer-reviewed literature, and over the past decade Quokka and Quokka3 have been used across a broad body of silicon and tandem solar-cell research — from record cells in Nature and Nature Energy to industrial device analysis. Below are the papers that define the simulator, followed by a selection of the work that applies it.

How to cite Quokka3

Please cite the Quokka3 “skin concept” paper (Fell et al., SOLMAT, 2017) as the primary reference. Where relevant, also cite the model paper matching your simulation — for example tandem cells (Fell et al., IEEE JPV, 2022).

The Quokka method papers

First-author papers describing the simulator and the physical and numerical models it implements. These are the references to cite when you use Quokka3.

  1. A free and fast three-dimensional/two-dimensional solar cell simulator featuring conductive boundary and quasi-neutrality approximations

    A. Fell · IEEE Transactions on Electron Devices 60(2), 733–738 · 2013

    Introduces Quokka: a free, fast 3-D/2-D silicon solar-cell simulator built on the quasi-neutrality and conductive-boundary approximations, which computes a full I–V curve in seconds to minutes on an ordinary PC. This is the canonical reference for the simulator.

    doi.org/10.1109/TED.2012.2231415 ↗
    The original Quokka paper
  2. Quokka version 2: selective surface doping, luminescence modeling and data fitting

    A. Fell · Proc. 23rd Int. Photovoltaic Science and Engineering Conf. (PVSEC-23) · 2013

    The Quokka 2 reference. Extends the simulator with selective surface doping, luminescence modelling, and integrated data fitting, broadening it from pure I–V simulation toward characterization and parameter extraction.

  3. The concept of skins for silicon solar cell modeling

    A. Fell, J. Schön, M. C. Schubert, S. W. Glunz · Solar Energy Materials & Solar Cells 173, 128–133 · 2017

    Introduces the “skin” concept underpinning Quokka3: thin near-surface regions (diffusions, passivating contacts, tandem top cells) are lumped into injection-dependent effective recombination and sheet-resistance parameters by a 1-D skin solver, then coupled to a fast multidimensional bulk solver. This enabled — for the first time — full 3-D simulation of an entire 156 mm cell, orders of magnitude faster than generic device simulators.

    doi.org/10.1016/j.solmat.2017.05.012 ↗
    Foundation of Quokka3
  4. 3-D simulation of interdigitated-back-contact silicon solar cells with Quokka including perimeter losses

    A. Fell, K. C. Fong, K. R. McIntosh, E. Franklin, A. W. Blakers · IEEE Journal of Photovoltaics 4(4), 1040–1045 · 2014

    Extends Quokka to full 3-D interdigitated-back-contact (IBC) cells with arbitrary contact and diffusion patterns, free-energy-loss analysis, and a method to capture cell-edge and busbar perimeter losses. Validated against measured high-efficiency IBC cells and against Sentaurus Device.

    doi.org/10.1109/JPHOTOV.2014.2320302 ↗
  5. Combining drift-diffusion and equivalent-circuit models for efficient 3D tandem solar cell simulations

    A. Fell, O. Schultz-Wittmann, C. Messmer, M. C. Schubert, S. W. Glunz · IEEE Journal of Photovoltaics 12(6), 1469–1476 · 2022

    Extends Quokka3 to tandem cells by coupling a 1-D equivalent-circuit top-cell model into the front boundary condition while the silicon bottom cell is solved in 3-D, so adding a perovskite top cell costs little extra computation. Makes full-area 3-D tandem simulation tractable, demonstrated on perovskite/silicon perimeter designs.

    doi.org/10.1109/JPHOTOV.2022.3209608 ↗
  6. Simplified device simulation of silicon solar cells using a lumped parameter optical model

    A. Fell, K. R. McIntosh, K. C. Fong · IEEE Journal of Photovoltaics 6(3), 611–616 · 2016

    A lumped-parameter optical model that reproduces ray-traced optical generation profiles from just the front-surface transmission and a path-length enhancement factor, with negligible error and near independence from spectrum, thickness, and temperature. Provides Quokka’s fast optical-generation input as an alternative to full ray tracing.

    doi.org/10.1109/JPHOTOV.2016.2528407 ↗
  7. Modeling edge recombination in silicon solar cells

    A. Fell, J. Schön, M. Müller, N. Wöhrle, M. C. Schubert, S. W. Glunz · IEEE Journal of Photovoltaics 8(2), 428–434 · 2018

    Adds a localized edge-recombination model to Quokka3, applying an edge-length-specific J02 directly on the 3-D cell boundary rather than as an external diode. Establishes a largely device-independent worst-case edge recombination of ~19 nA/cm and clarifies why edge losses appear differently in the dark and illuminated I–V.

    doi.org/10.1109/JPHOTOV.2017.2787020 ↗
  8. Adaption of basic metal-insulator-semiconductor (MIS) theory for passivating contacts within numerical solar cell modeling

    A. Fell, F. Feldmann, C. Messmer, M. Bivour, M. C. Schubert, S. W. Glunz · IEEE Journal of Photovoltaics 8(6), 1546–1552 · 2018

    Adapts basic metal-insulator-semiconductor theory into a physically-based boundary condition (a “skin”) for passivating contacts such as TOPCon and SHJ, capturing non-ohmic contact resistivity, injection-dependent recombination, and current-independent voltage drops that the simple lumped approach misses. Reproduces the fill-factor temperature dependence of TOPCon cells from very few parameters.

    doi.org/10.1109/JPHOTOV.2018.2871953 ↗
  9. Radiative recombination in silicon photovoltaics: Modeling the influence of charge carrier densities and photon recycling

    A. Fell, T. Niewelt, B. Steinhauser, F. D. Heinz, M. C. Schubert, S. W. Glunz · Solar Energy Materials & Solar Cells 230, 111198 · 2021

    Reassesses the carrier-density dependence of silicon’s radiative recombination coefficient, photon recycling, and free-carrier absorption, and proposes a photon-recycling scaling factor. Shows that above ~1e16 cm⁻³ free-carrier absorption breaks the proportionality between luminescence signal and radiative recombination — important for interpreting calibrated photoluminescence-lifetime measurements.

    doi.org/10.1016/j.solmat.2021.111198 ↗
  10. Modeling parasitic absorption in silicon solar cells with a near-surface absorption parameter

    A. Fell, J. Greulich, F. Feldmann, C. Messmer, J. Schön, M. Bivour, M. C. Schubert, S. W. Glunz · Solar Energy Materials & Solar Cells 236, 111534 · 2022

    Introduces a near-surface absorption parameter (Appp) that quantifies parasitic absorption in passivating-contact layers (poly-Si, a-Si, TCO) from a single value fitted to reflectance, avoiding the need to know every layer’s optical constants. Proposes Appp as a third passivating-contact figure of merit alongside J0,c and contact resistivity.

    doi.org/10.1016/j.solmat.2021.111534 ↗
  11. Input parameters for the simulation of silicon solar cells in 2014

    A. Fell, K. R. McIntosh, P. P. Altermatt, et al. · IEEE Journal of Photovoltaics 5(4), 1250–1263 · 2015

    A multi-institution reference review providing complete, justified input-parameter sets for simulating six major crystalline-silicon cell types, intended as a consistent and reproducible starting point. Widely used as the community benchmark for silicon-cell simulation inputs.

    doi.org/10.1109/JPHOTOV.2015.2430016 ↗
    Community reference
  12. A detailed full-cell model of a 2018 commercial PERC solar cell in Quokka3

    A. Fell, P. P. Altermatt · IEEE Journal of Photovoltaics 8(6), 1443–1448 · 2018

    A fully documented full-cell model of a state-of-the-art 2018 commercial PERC cell, using a new multidomain approach so the entire 156 mm 3-D geometry — including the emitter skins — is solved in a single simulation. Provides a complete reference input-parameter set and loss breakdown for modelling industrial PERC cells.

    doi.org/10.1109/JPHOTOV.2018.2863548 ↗
  13. Elucidating the efficiency limit of silicon-based monolithic tandem cells through the combination of Auger and Shockley–Queisser limits

    A. Fell, O. Fischer, M. Bivour, C. Messmer, J. Schön, M. C. Schubert, S. W. Glunz · EES Solar 1, 1030–1039 · 2025

    Combines state-of-the-art silicon Auger-recombination modelling with Shockley–Queisser top-cell limits to establish realistic efficiency limits for silicon-based tandems, implemented in Quokka3. Finds a maximum two-terminal efficiency of 43.2% (optimal top-cell bandgap 1.71 eV, 300 µm silicon), below the 45.2% from idealized assumptions, and provides lookup tables for device optimization.

    doi.org/10.1039/D5EL00085H ↗

Applications

Research that uses Quokka or Quokka3 to design, analyse, or understand solar cells — including the author's own collaborations and independent work by other groups. Ordered by citation count.

  1. n-Type Si solar cells with passivating electron contact: Identifying sources for efficiency limitations by wafer thickness and resistivity variation

    A. Richter, J. Benick, F. Feldmann, A. Fell, M. Hermle, S. W. Glunz · Solar Energy Materials & Solar Cells 173, 96–105 · 2017

    Combines wafer thickness and resistivity variation with 3-D full-area Quokka simulations to identify the recombination sources limiting n-type TOPCon cells, pinpointing SRH bulk recombination as the cause of fill-factor loss in high-resistivity silicon. Using 1 Ω·cm silicon achieved a then-record 25.7% efficiency for both-sides-contacted c-Si.

    doi.org/10.1016/j.solmat.2017.05.042 ↗
    25.7% record TOPCon
  2. Silicon heterojunction solar cells with up to 26.81% efficiency achieved by electrically optimized nanocrystalline-silicon hole contact layers

    H. Lin, M. Yang, X. Ru, G. Wang, S. Yin, F. Peng, et al. · Nature Energy 8, 789–799 · 2023

    Reports LONGi's silicon heterojunction (SHJ) cell reaching 26.81% — at publication the highest efficiency for any crystalline-silicon solar cell — enabled by electrically optimized nanocrystalline-silicon hole-contact layers. A widely cited milestone within the high-efficiency-silicon literature that draws on Quokka device modelling.

    doi.org/10.1038/s41560-023-01255-2 ↗
    26.81% — c-Si record
  3. Design rules for high-efficiency both-sides-contacted silicon solar cells with balanced charge carrier transport and recombination losses

    A. Richter, R. Müller, J. Benick, F. Feldmann, A. Fell, M. Bivour, M. Hermle, S. W. Glunz · Nature Energy 6(4), 429–438 · 2021

    Shows that omitting front-side lateral-transport layers is key to top optoelectrical performance, demonstrating a 26.0% both-sides-contacted cell whose junction is a full-area rear poly-Si passivating contact. A simulation-based power-loss analysis yields fundamental design rules for future >26% both-sides-contacted silicon cells.

    doi.org/10.1038/s41560-021-00805-w ↗
    26.0% cell + design rules
  4. Enhanced optoelectronic coupling for perovskite/silicon tandem solar cells

    E. Aydin, E. Ugur, B. K. Yildirim, … A. Fell, C. Xiao, S. De Wolf · Nature 623(7988), 732–738 · 2023

    Replaces the crystalline interconnecting TCO in monolithic perovskite/silicon tandems with ultrathin (5 nm) amorphous IZO for more homogeneous hole-selective contacts on textured silicon, reaching an independently certified 32.5% efficiency while cutting indium use by ~80%. Quokka3 device simulation supported the optoelectronic analysis.

    doi.org/10.1038/s41586-023-06667-4 ↗
    32.5% certified tandem
  5. Design, fabrication and characterisation of a 24.4% efficient interdigitated back contact solar cell

    E. Franklin, K. Fong, K. McIntosh, A. Fell, et al. · Progress in Photovoltaics 24(4), 411–427 · 2016

    Design, fabrication, and full 3-D loss analysis of an ANU interdigitated-back-contact cell reaching an independently confirmed 24.4%. Measured optical and electronic properties were fed into Quokka 3-D modelling to quantify every loss mechanism and chart a route beyond 25%.

    doi.org/10.1002/pip.2556 ↗
    24.4% IBC
  6. Reassessment of the intrinsic bulk recombination in crystalline silicon

    T. Niewelt, B. Steinhauser, A. Richter, A. Fell, et al. · Solar Energy Materials & Solar Cells 235, 111467 · 2022

    Reassesses intrinsic (Auger + radiative) recombination in crystalline silicon from a dedicated set of high-quality samples, deriving an improved Coulomb-enhanced Auger parameterization valid across all relevant doping and injection. Quokka3 is then used to compute the resulting fundamental single-junction silicon efficiency limit of 29.4% — now a widely used reference value.

    doi.org/10.1016/j.solmat.2021.111467 ↗
    29.4% c-Si limit
  7. Monolithic perovskite/Si tandem solar cells: Pathways to over 30% efficiency

    H. Shen, D. Walter, Y. Wu, K. C. Fong, et al. · Advanced Energy Materials 10(13), 1902840 · 2020

    A combined modelling and experimental study mapping the loss mechanisms and design pathways for monolithic perovskite/silicon tandems toward >30% efficiency, spanning optical coupling, recombination, and current matching. A widely cited roadmap for the tandem field.

    doi.org/10.1002/aenm.201902840 ↗
  8. Nanoscale back contact perovskite solar cell design for improved tandem efficiency

    G. W. P. Adhyaksa, E. Johlin, E. C. Garnett · Nano Letters 17(9), 5206–5212 · 2017

    Uses optical and device modelling to propose nanoscale back-contact perovskite cell designs that reduce parasitic absorption and improve current collection, raising the achievable efficiency of perovskite/silicon tandems.

    doi.org/10.1021/acs.nanolett.7b01092 ↗
  9. Transient photovoltage in perovskite solar cells: Interaction of trap-mediated recombination and migration of multiple ionic species

    D. Walter, A. Fell, Y. Wu, T. Duong, et al. · Journal of Physical Chemistry C 122(21), 11270–11281 · 2018

    A numerical drift-diffusion model of perovskite cells including migration of multiple ionic species coupled to trap-mediated recombination, explaining both J–V hysteresis and unusual nonmonotonic photovoltage transients. Identifies modulation of the recombination profile by net ionic charge as the unifying mechanism.

    doi.org/10.1021/acs.jpcc.8b02529 ↗
  10. Efficiency roadmap for evolutionary upgrades of PERC solar cells by TOPCon: Impact of parasitic absorption

    C. Messmer, A. Fell, F. Feldmann, N. Wöhrle, J. Schön, M. Hermle · IEEE Journal of Photovoltaics 10(2), 335–342 · 2020

    A simulation-based efficiency roadmap (Quokka3 electrical plus Sentaurus optics) for evolutionarily upgrading p-PERC cells with TOPCon passivating contacts, explicitly accounting for parasitic free-carrier absorption in the poly-Si. Full rear plus front-aligned TOPCon can add ~1% absolute efficiency.

    doi.org/10.1109/JPHOTOV.2019.2957642 ↗
  11. Passivation of all-angle black surfaces for silicon solar cells

    T. Rahman, R. S. Bonilla, A. Nawabjan, et al. · Solar Energy Materials & Solar Cells 160, 444–453 · 2017

    Studies surface passivation of black-silicon (all-angle textured) surfaces and its impact on recombination and reflectance, combining experiment with device modelling to assess the efficiency potential of black-silicon cells.

    doi.org/10.1016/j.solmat.2016.10.044 ↗
  12. Towards the efficiency limits of multicrystalline silicon solar cells

    F. Schindler, A. Fell, R. Müller, J. Benick, A. Richter, et al. · Solar Energy Materials & Solar Cells 185, 198–204 · 2018

    Reports a certified world-record 22.3% n-type high-performance multicrystalline silicon TOPCon cell and a detailed loss analysis of the record batch, attributing the gap to FZ references mainly to grain-boundary and emitter recombination. Projects ~23% achievable mc-Si efficiency.

    doi.org/10.1016/j.solmat.2018.05.006 ↗
    22.3% mc-Si record
  13. Progress of plated metallization for industrial bifacial TOPCon silicon solar cells

    B. Grübel, G. Cimiotti, C. Schmiga, et al. · Progress in Photovoltaics 30(6), 615–626 · 2022

    Develops plated Cu metallization for industrial bifacial TOPCon cells and analyses the resulting contact and resistive losses, supporting the case for plating as a silver-free industrial metallization route.

    doi.org/10.1002/pip.3528 ↗
  14. A study on the charge carrier transport of passivating contacts

    F. Feldmann, G. Nogay, J.-I. Polzin, B. Steinhauser, A. Richter, A. Fell, et al. · IEEE Journal of Photovoltaics 8(6), 1503–1509 · 2018

    Investigates charge-carrier transport across the interfacial oxide of TOPCon passivating contacts, distinguishing tunneling-dominated from pinhole-dominated devices. Quokka3 with the MIS boundary condition reproduces the measured temperature dependence of the fill factor, linking the FF behaviour to partial crystallization of the poly-Si layer.

    doi.org/10.1109/JPHOTOV.2018.2870735 ↗
  15. Evolutionary PERC+ solar cell efficiency projection towards 24%

    T. Dullweber, M. Stöhr, C. Kruse, F. Haase, et al. · Solar Energy Materials & Solar Cells 212, 110586 · 2020

    A device-simulation efficiency projection for evolutionary PERC+ upgrades toward 24%, evaluating poly-Si fingers beneath the front contact and other incremental improvements to the industrial PERC architecture.

    doi.org/10.1016/j.solmat.2020.110586 ↗
  16. Simulation-based roadmap for the integration of poly-silicon on oxide contacts into screen-printed crystalline silicon solar cells

    C. N. Kruse, S. Schäfer, F. Haase, V. Mertens, et al. · Scientific Reports 11, 996 · 2021

    A simulation-based roadmap for integrating poly-Si/oxide (TOPCon) passivating contacts into screen-printed industrial silicon cells, quantifying the efficiency gains of each integration step.

    doi.org/10.1038/s41598-020-79591-6 ↗
  17. Optimized front TCO and metal grid electrode for module-integrated perovskite–silicon tandem solar cells

    C. Messmer, L. Tutsch, S. Pingel, D. Erath, J. Schön, A. Fell, et al. · Progress in Photovoltaics 30(4), 374–383 · 2022

    Optimizes the front transparent-conductive-oxide (TCO) and metallization grid for module-integrated perovskite/silicon tandems, balancing optical, resistive, and shading losses. Quokka3 device simulation shows the front ITO can be thinned from ~75 nm to ~20 nm — cutting indium use — without an efficiency penalty once the grid is co-optimized.

    doi.org/10.1002/pip.3491 ↗
  18. The electrical properties of high performance multicrystalline silicon and mono-like silicon: Material limitations and cell potential

    H. C. Sio, S. P. Phang, A. Fell, D. Macdonald, et al. · Solar Energy Materials & Solar Cells 201, 110059 · 2019

    Characterizes bulk lifetime and defect recombination of high-performance multicrystalline and mono-like silicon, then applies Quokka3 to simulate each material’s cell-efficiency potential and partition the loss by mechanism. Identifies n-type mono-like silicon as the most promising material.

    doi.org/10.1016/j.solmat.2019.110059 ↗
  19. Interfacial dynamics and contact passivation in perovskite solar cells

    M. De Bastiani, E. Aydin, T. Allen, D. Walter, A. Fell, et al. · Advanced Electronic Materials 5(1), 1800500 · 2019

    Combines transient photocurrent measurements with device simulation to separate slow ion migration from fast interfacial recombination in perovskite cells, identifying interfacial charge accumulation as the driver of hysteresis and Voc loss. A passivating interlayer renders the devices hysteresis-free.

    doi.org/10.1002/aelm.201800500 ↗
  20. High efficiency UMG silicon solar cells: Impact of compensation on cell parameters

    F. Rougieux, C. Samundsett, K. C. Fong, A. Fell, P. Zheng, D. Macdonald, et al. · Progress in Photovoltaics 24(5), 725–734 · 2016

    Fabricates high-efficiency n-type Czochralski cells (up to 19.8%) from 100% upgraded-metallurgical-grade (UMG) silicon feedstock. Quokka simulations comparing UMG-Cz against electronic-grade cells show that bulk lifetime — not dopant-compensation effects on mobility or resistivity — remains the primary efficiency limit for the UMG material.

    doi.org/10.1002/pip.2729 ↗
  21. The impact of mobile ions on the steady-state performance of perovskite solar cells

    N. Wu, D. Walter, A. Fell, Y. Wu, K. Weber · Journal of Physical Chemistry C 124(1), 219–229 · 2019

    Uses ionic drift-diffusion modelling to show that mobile ions need not degrade the steady-state efficiency of perovskite cells, only doing so when the carrier mobility–lifetime product is limited. Concludes that removing nonradiative recombination counteracts the impact of mobile ions.

    doi.org/10.1021/acs.jpcc.9b10578 ↗
  22. Characterization of recombination properties and contact resistivity of laser-processed localized contacts from doped silicon nanoparticle ink and spin-on dopants

    M. Ernst, A. Fell, E. Franklin, K. J. Weber · IEEE Journal of Photovoltaics 7(2), 471–478 · 2017

    Introduces test structures and Quokka 3-D simulation to separately extract the recombination parameter J0,c and the contact resistivity of laser-doped localized contacts, resolving J0,c down to 300 fA/cm² and ρc down to 1e-4 Ω·cm². Projects a 23.7% efficiency potential for laser-doped IBC cells.

    doi.org/10.1109/JPHOTOV.2017.2655028 ↗
  23. Quantifying surface recombination — Improvements in determination and simulation of the surface recombination parameter J0s

    B. Hammann, B. Steinhauser, A. Fell, et al. · IEEE Journal of Photovoltaics 13(4), 535–546 · 2023

    Improves how the surface recombination parameter J0s is obtained from lifetime data and from device simulations, and quantifies the error (up to 50% in simulated emitters) introduced by pairing it with an outdated intrinsic-recombination model. Provides an updated, self-consistent J0s parameterization.

    doi.org/10.1109/JPHOTOV.2023.3265859 ↗
  24. Impact of bulk impurity contamination on the performance of high-efficiency n-type silicon solar cells

    A. Richter, J. Benick, A. Fell, M. Hermle, S. W. Glunz · Progress in Photovoltaics 26(5), 342–350 · 2018

    Uses Quokka3 simulations with reported Shockley–Read–Hall parameters of common metal impurities (Fe, Cr, Ni…) to quantify how bulk impurity contamination limits high-efficiency n-type silicon cells. Identifies bulk impurity recombination as a dominant efficiency loss for high-resistivity silicon and assesses which impurity signatures can be distinguished from cell measurements.

    doi.org/10.1002/pip.2990 ↗
  25. Self-aligned selective area front contacts on poly-Si/SiOx passivating contact c-Si solar cells

    K. Chen, B. Hartweg, M. Woodhouse, et al. · IEEE Journal of Photovoltaics 12(2), 502–509 · 2022

    Demonstrates a self-aligned selective-area front-contact scheme for poly-Si/SiOx passivating-contact cells and uses device simulation to quantify the trade-off between contact recombination and series resistance.

    doi.org/10.1109/JPHOTOV.2021.3138552 ↗
  26. Numerical simulations of photoluminescence for the precise determination of emitter contact recombination parameters

    D. Herrmann, S. Lohmüller, H. Höffler, A. Fell, A. A. Brand, A. Wolf · IEEE Journal of Photovoltaics 9(6), 1759–1767 · 2019

    Uses Quokka3 to simulate photoluminescence images of metallized test structures so the emitter-contact recombination parameter J0,met can be extracted while correctly accounting for the non-uniform excess-carrier density that biases simpler evaluations. Establishes a more precise, simulation-grounded route to quantifying contact recombination.

    doi.org/10.1109/JPHOTOV.2019.2938400 ↗
  27. Prediction of local temperature-dependent performance of silicon solar cells

    R. Eberle, A. Fell, S. Mägdefessel, F. Schindler, M. C. Schubert · Progress in Photovoltaics 27(11), 999–1006 · 2019

    Predicts the spatially resolved, temperature-dependent performance (Voc, Jsc, FF, efficiency) of a virtual silicon cell directly from injection- and temperature-dependent lifetime images, by combining calibrated photoluminescence imaging with Quokka3 device simulation. Enables local investigation of cell parameters under realistic operating temperatures.

    doi.org/10.1002/pip.3130 ↗
  28. Perimeter recombination characterization by luminescence imaging

    K. C. Fong, M. Padilla, A. Fell, et al. · IEEE Journal of Photovoltaics 6(1), 244–251 · 2016

    A luminescence-imaging method to extract cell-perimeter recombination from cells left embedded in the wafer, validated against 2-D device simulation. Sensitive enough to detect perimeter loss in an IBC cell whose J–V curve shows no obvious non-ideality.

    doi.org/10.1109/JPHOTOV.2015.2480225 ↗
  29. Efficiency potential of p-type Al2O3/SiNx passivated PERC solar cells with locally laser-doped rear contacts

    M. Ernst, D. Walter, A. Fell, B. Lim, K. Weber · IEEE Journal of Photovoltaics 6(3), 624–631 · 2016

    Demonstrates simultaneous rear contact-opening and doping on large-area (156 mm) p-type Al2O3/SiNx PERC cells using UV and green laser processing, reaching up to 19.9%. 3-D device simulations show a further ~0.3% absolute efficiency gain is attainable with 5 µm laser point contacts at J0,c ≈ 5000 fA/cm² and ρc ≈ 1e-4 Ω·cm².

    doi.org/10.1109/JPHOTOV.2016.2535353 ↗
  30. 22.8% full-area bifacial n-PERT solar cells with rear side sputtered poly-Si (n) passivating contact

    A. Ingenito, C. Allebé, S. Libraro, C. Ballif, et al. · Solar Energy Materials & Solar Cells 249, 112043 · 2023

    Fabricates 22.8% full-area bifacial n-PERT cells with a sputtered poly-Si rear passivating contact, using device simulation to analyse the contact and bulk losses limiting the architecture.

    doi.org/10.1016/j.solmat.2022.112043 ↗
    22.8% bifacial
  31. Analysis of passivation property using thin Al2O3 layer and simulation for realization of high-efficiency TOPCon cell

    S. Chowdhury, G. Chavan, S. Kim, D. Oh, Y. Kim, et al. · Infrared Physics & Technology 108, 103341 · 2020

    Combines Al2O3-passivation measurements with Quokka simulation to project the efficiency potential of TOPCon cells, identifying the passivation and contact parameters that most constrain performance.

    doi.org/10.1016/j.infrared.2020.103341 ↗
  32. Characterization of laser-doped localized p-n junctions for high efficiency silicon solar cells

    A. Fell, S. Surve, E. Franklin, K. J. Weber · IEEE Transactions on Electron Devices 61(6), 1943–1949 · 2014

    Fits measured dark I–V curves with 3-D Quokka simulations to extract the contact resistance and dark saturation current of laser-doped localized p–n junctions. Identifies a ~24% efficiency potential for a non-optimized two-step laser-doping process.

    doi.org/10.1109/TED.2014.2318714 ↗
  33. Spatially resolved determination of metallization-induced recombination losses using photoluminescence imaging

    D. Herrmann, D. R. C. Falconi, S. Lohmüller, D. Ourinson, A. Fell, H. Höffler, A. A. Brand, A. Wolf · IEEE Journal of Photovoltaics 11(1), 174–184 · 2021

    Develops a spatially resolved method to map metallization-induced recombination losses from photoluminescence images, using an interpolation scheme to predict the PL signal of a virtually non-metallized reference (to ~0.7% relative deviation) together with device simulation to extract the local contact recombination parameter J0,met.

    doi.org/10.1109/JPHOTOV.2020.3038336 ↗
  34. A step-by-step optimization of the c-Si bottom cell in monolithic perovskite/c-Si tandem devices

    Y. L. Wu, A. Fell, K. J. Weber · Solar RRL 2(11), 1800193 · 2018

    Opto-electrical modelling (SunSolve plus Quokka3) to optimize the silicon bottom cell in monolithic perovskite/silicon tandems, finding low-resistivity p-type wafers can outperform n-type and proposing two new bottom-cell architectures for >30% tandems.

    doi.org/10.1002/solr.201800193 ↗
  35. Realization and simulation of interdigitated back contact silicon solar cells with dopant-free asymmetric hetero-contacts

    W. Wang, J. He, D. Yan, W. Chen, S. P. Phang, et al. · Solar Energy 211, 324–333 · 2022

    Realizes and simulates IBC silicon cells using dopant-free asymmetric hetero-contacts, with Quokka 3-D simulation used to understand the loss mechanisms and design space of the dopant-free architecture.

    doi.org/10.1016/j.solener.2020.09.085 ↗
  36. Revised parametrization of the recombination velocity at SiO2/SiNx-passivated phosphorus-diffused surfaces

    A. Wolf, J. Egle, S. Mack, … A. Fell, et al. · Solar Energy Materials & Solar Cells 231, 111292 · 2021

    Derives a revised, calibration-consistent parameterization of the effective surface recombination velocity for the industrially common SiO2/SiNx phosphorus-emitter passivation, using numerical simulation to separate field-effect from chemical passivation. Improves prediction of emitter J0 from the doping profile.

    doi.org/10.1016/j.solmat.2021.111292 ↗
  37. Local series resistance imaging of silicon solar cells with complex current paths

    M. Padilla, B. Michl, … A. Fell, … M. C. Schubert · IEEE Journal of Photovoltaics 5(3), 752–758 · 2015

    Extends luminescence-based local series-resistance imaging to cells with complex, asymmetric current paths (such as IBC), supported by a conductive-boundary I–V and luminescence simulation. Achieves ±30% agreement between averaged local and global series resistance.

    doi.org/10.1109/JPHOTOV.2015.2397595 ↗
  38. The impact of measurement conditions on solar cell efficiency

    M. Rauer, A. Fell, W. Wöhler, D. Hinken, et al. · Solar RRL 8(3), 2300873 · 2024

    Quantifies, via Quokka3 simulation and measurement, how cell measurement conditions and busbar concept can shift measured efficiency by up to 0.5% absolute, and how cell-level gains do not map identically onto module level. Proposes a notation to specify measurement conditions unambiguously.

    doi.org/10.1002/solr.202300873 ↗
  39. 3-D modeling of multicrystalline silicon materials and solar cells

    H. C. Sio, A. Fell, S. P. Phang, et al. · IEEE Journal of Photovoltaics 9(4), 965–973 · 2019

    Models large-area multicrystalline silicon in Quokka3 using synthetic lifetime images that combine injection-dependent intra-grain lifetime with defect recombination maps from photoluminescence. Shows lifetime-image-only simulations underestimate defect harm and overestimate performance.

    doi.org/10.1109/JPHOTOV.2019.2914874 ↗
  40. Parameterization of the back-surface reflection for PERC solar cells including variation of back-contact coverage

    A. Alapont Sabater, A. Fell, A. A. Brand, M. Müller, J. M. Greulich · IEEE Journal of Photovoltaics 11(5), 1136–1140 · 2021

    Tests Basore’s analytical light-trapping model (as implemented in Quokka3) for capturing the optical effect of rear-contact pitch in PERC cells, deriving simple linear parameterizations that replace slower ray tracing for metallization-fraction variation.

    doi.org/10.1109/JPHOTOV.2021.3082402 ↗
  41. Mitigation of shunt in poly-Si/SiOx passivated interdigitated back contact monocrystalline Si solar cells by self-aligned etching between doped fingers

    M. B. Hartenstein, W. Nemeth, K. Chen, … A. Fell, et al. · Solar Energy Materials & Solar Cells 252, 112195 · 2023

    Mitigates inter-finger shunting in poly-Si/SiOx IBC cells by a self-aligned etch of the isolation region, gaining 11.7% in fill factor. Quokka3 simulation identifies junction recombination (J02) in the isolation region as the dominant remaining loss.

    doi.org/10.1016/j.solmat.2023.112195 ↗
  42. Assessing current-voltage measurements of busbarless solar cells

    M. Rauer, A. Krieg, A. Fell, et al. · Solar Energy Materials & Solar Cells 248, 111988 · 2022

    Shows the (unstandardized) contacting configuration used to measure busbarless cells can change measured fill factor and efficiency by over 10% relative, and provides a Quokka3-validated analytical method to convert I–V results between measurement and module configurations.

    doi.org/10.1016/j.solmat.2022.111988 ↗
  43. Breakdown of temperature sensitivity of silicon solar cells by simulation input parameters

    R. Eberle, A. Fell, F. Schindler, J. Shahid, M. C. Schubert · Solar Energy Materials & Solar Cells 219, 110836 · 2021

    Extends Quokka3’s lumped-skin model to include the temperature dependence of bulk lifetime and skin recombination, then decomposes a PERC cell’s temperature sensitivity contribution by contribution. Finds these previously-neglected dependences matter little for typical PERC, while flagging remaining uncertainty for contacts and lowly-doped surfaces.

    doi.org/10.1016/j.solmat.2020.110836 ↗
  44. Influence of fundamental model uncertainties on silicon solar cell efficiency simulations

    S. Wasmer, A. Fell, J. M. Greulich · IEEE Transactions on Electron Devices 66(1), 277–283 · 2019

    Propagates the uncertainties of fundamental physical models (bandgap narrowing, Auger, free-carrier absorption) through to simulated silicon-cell efficiency. Finds intrinsic model uncertainty is small (~0.1% absolute) but the choice of bandgap-narrowing model can shift efficiency by up to 0.6% absolute.

    doi.org/10.1109/TED.2018.2882776 ↗
  45. Back-contacted back-junction Si solar cells with locally overcompensated diffusion regions — Comparison of buried emitter and floating base design

    C. Reichel, A. Fell, M. Hermle, S. W. Glunz · Physica Status Solidi A 216(15), 1800791 · 2019

    Numerical and experimental comparison of two back-contacted back-junction cell designs with locally overcompensated diffusions, showing the buried-emitter design (21.4%) strongly outperforms the floating-base design (17.1%). 2-D device simulation attributes the floating-base losses to junction leakage and emitter-surface recombination.

    doi.org/10.1002/pssa.201800791 ↗
  46. Is shunt quenching relevant to minimize shunt losses in perovskite-silicon tandem solar cells?

    A. Fell, M. Bivour, C. Messmer, M. Hermle · Solar RRL 8, 2400571 · 2024

    A comprehensive 3-D device-simulation study of whether “shunt-quenching” strategies (current mismatch, intermediate-layer resistance engineering) reduce local shunt losses in perovskite/silicon tandems. Concludes both are largely ineffective except for strong, macroscopically distributed shunts under specific conditions.

    doi.org/10.1002/solr.202400571 ↗

Further work using Quokka

An incomplete and growing selection of additional third-party papers that use or build on Quokka. If your paper uses Quokka3 and isn't listed, let us know.