Veröffentlichungen
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S. Schäfer, A. Mercker, A. Köhler, T. Neubert, L. Mettner, B. Wolpensinger, V. Mertens, and R. Peibst Journal of Applied Physics 129 (13), 133103, (2021). Abstract | Links | BibTeX | Schlagwörter: Chemical elements, Chemical processes, electric measurements, Lasers, optical properties, passivation, Semiconductor materials, silicon, Solar Cells, Transmission electron microscopy @article{Schäfer2021,
title = {Role of oxygen in the UV-ps laser triggered amorphization of poly-Si for Si solar cells with local passivated contacts}, author = {S Schäfer and A Mercker and A Köhler and T Neubert and L Mettner and B Wolpensinger and V Mertens and R Peibst}, doi = {10.1063/5.0045829}, year = {2021}, date = {2021-04-07}, journal = {Journal of Applied Physics}, volume = {129}, number = {13}, pages = {133103}, abstract = {In recent years, poly-Si based passivated contacts elevated the conversion efficiencies of crystalline Si solar cells to levels of 26%abs due to their outstanding electrical surface passivation performance and current transport characteristics. A major associated challenge, however, is the large parasitic light absorption within the doped poly-Si, regardless if the contacts are applied on the front and/or on the rear side of the solar cell. It, therefore, might be beneficial to confine the passivated contacts to local regions underneath the metal contacts. We present an effective and flexible laser-based approach to structure the poly-Si layer after its full-area deposition. Laser pulses with a pulse duration of 9 ps and a wavelength of 355 nm trigger an amorphization of the poly-Si surface. The minimum threshold fluence for amorphization is between 89 and 129 mJ/cm2. The a-Si layer, which is laterally homogeneous and up to (33 ± 4) nm in thickness, works as an etch barrier in an alkaline solution. The most robust barrier corresponding to the maximum thickness of the a-Si layer is found for a fluence of (270 ± 30) mJ/cm2. Besides the impact of the laser fluence on the etch resistiveness of the modified poly-Si layer, we study the role of oxygen during the laser process. We find that oxygen becomes incorporated into the material for certain laser fluences, which results in a more robust etch barrier. The amount of oxygen incorporated is below 3 wt. %. Eventually, we present a phenomenological model of our findings.}, keywords = {Chemical elements, Chemical processes, electric measurements, Lasers, optical properties, passivation, Semiconductor materials, silicon, Solar Cells, Transmission electron microscopy}, pubstate = {published}, tppubtype = {article} } In recent years, poly-Si based passivated contacts elevated the conversion efficiencies of crystalline Si solar cells to levels of 26%abs due to their outstanding electrical surface passivation performance and current transport characteristics. A major associated challenge, however, is the large parasitic light absorption within the doped poly-Si, regardless if the contacts are applied on the front and/or on the rear side of the solar cell. It, therefore, might be beneficial to confine the passivated contacts to local regions underneath the metal contacts. We present an effective and flexible laser-based approach to structure the poly-Si layer after its full-area deposition. Laser pulses with a pulse duration of 9 ps and a wavelength of 355 nm trigger an amorphization of the poly-Si surface. The minimum threshold fluence for amorphization is between 89 and 129 mJ/cm2. The a-Si layer, which is laterally homogeneous and up to (33 ± 4) nm in thickness, works as an etch barrier in an alkaline solution. The most robust barrier corresponding to the maximum thickness of the a-Si layer is found for a fluence of (270 ± 30) mJ/cm2. Besides the impact of the laser fluence on the etch resistiveness of the modified poly-Si layer, we study the role of oxygen during the laser process. We find that oxygen becomes incorporated into the material for certain laser fluences, which results in a more robust etch barrier. The amount of oxygen incorporated is below 3 wt. %. Eventually, we present a phenomenological model of our findings.
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M-U. Halbich, and J. Schmidt physica status solidi (RRL) – Rapid Research Letters 15 (4), 2100008, (2021). Abstract | Links | BibTeX | Schlagwörter: carrier lifetimes, depletion region modulation, heterojunctions, PEDOT:PSS, silicon @article{Halbich2021,
title = {Extraction of PEDOT:PSS/c-Si Junction Properties by Modeling of Injection-Dependent Lifetime Measurements Including Depletion Region Modulation}, author = {M-U Halbich and J Schmidt}, doi = {10.1002/pssr.202100008}, year = {2021}, date = {2021-04-01}, journal = {physica status solidi (RRL) – Rapid Research Letters}, volume = {15}, number = {4}, pages = {2100008}, abstract = {The carrier lifetime of n-type silicon wafers coated with the conducting polymer PEDOT:PSS as a function of the excess carrier concentration Δp within the wafer is characterized using the quasi-steady-state photoconductance (QSSPC) method, and a drastic increase in the measured apparent lifetime τapp with decreasing Δp is observed. The observed increase with the depletion region modulation (DRM) effect is explained, as PEDOT:PSS-coated p-type silicon wafers do not show any increase in lifetime toward low injection levels. By modeling the measured τapp(Δp) curves on n-type silicon including interface recombination as well as the DRM effect, the interface recombination velocity as well as the band bending Ψs within the silicon induced by PEDOT:PSS are able to be extracted. The impact of adding sorbitol to the PEDOT:PSS dispersion on the τapp(Δp) curves is examined, and it is demonstrated that the admixture of sorbitol improves chemical interface passivation but leaves the band bending within the silicon bulk toward the PEDOT:PSS/c-Si interface unaffected.}, keywords = {carrier lifetimes, depletion region modulation, heterojunctions, PEDOT:PSS, silicon}, pubstate = {published}, tppubtype = {article} } The carrier lifetime of n-type silicon wafers coated with the conducting polymer PEDOT:PSS as a function of the excess carrier concentration Δp within the wafer is characterized using the quasi-steady-state photoconductance (QSSPC) method, and a drastic increase in the measured apparent lifetime τapp with decreasing Δp is observed. The observed increase with the depletion region modulation (DRM) effect is explained, as PEDOT:PSS-coated p-type silicon wafers do not show any increase in lifetime toward low injection levels. By modeling the measured τapp(Δp) curves on n-type silicon including interface recombination as well as the DRM effect, the interface recombination velocity as well as the band bending Ψs within the silicon induced by PEDOT:PSS are able to be extracted. The impact of adding sorbitol to the PEDOT:PSS dispersion on the τapp(Δp) curves is examined, and it is demonstrated that the admixture of sorbitol improves chemical interface passivation but leaves the band bending within the silicon bulk toward the PEDOT:PSS/c-Si interface unaffected.
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B. Lim Solarenergienutzung an Gebäuden Presentation/Poster Online Event, 25.03.2021, (Alles wird Kraftwerk - Webinar-Reihe "innovativ jetzt - Forschen für Nachhaltigkeit"). BibTeX | Schlagwörter: Gebäude @misc{Lim2021,
title = {Solarenergienutzung an Gebäuden}, author = {B Lim}, year = {2021}, date = {2021-03-25}, address = {Online Event}, note = {Alles wird Kraftwerk - Webinar-Reihe "innovativ jetzt - Forschen für Nachhaltigkeit"}, keywords = {Gebäude}, pubstate = {published}, tppubtype = {presentation} } |
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F. Haase, B. Min, C. Hollemann, J. Krügener, R. Brendel, and R. Peibst Fully screen-printed silicon solar cells with local Al-p+ and n-type POLO interdigitated back contacts with a VOC of 716 mV and an efficiency of 23% Artikel Forthcoming Progress in Photovoltaics: Research and Applications Forthcoming. Abstract | Links | BibTeX | Schlagwörter: IBC solar cells, local Al-p+, passivating contacts, POLO @article{Haase2021,
title = {Fully screen-printed silicon solar cells with local Al-p+ and n-type POLO interdigitated back contacts with a VOC of 716 mV and an efficiency of 23%}, author = {F Haase and B Min and C Hollemann and J Krügener and R Brendel and R Peibst}, doi = {https://doi.org/10.1002/pip.3399}, year = {2021}, date = {2021-03-05}, journal = {Progress in Photovoltaics: Research and Applications}, abstract = {Abstract We demonstrate the fabrication of a fully screen-printed p-type silicon solar cell with local hole-collecting Al-alloyed (Al-p+) contacts with a record open circuit voltage of 716 mV. The solar cell is fabricated by using almost the same process equipment as PERC cells. One of the dominant recombination losses in PERC cells is the recombination in the passivated and in the contacted emitter regions that so far limit the open circuit voltage to values below 700 mV. We eliminate these loss channels by substituting the P-diffused emitter by a passivating n-type poly-Silicon on Oxide (nPOLO) contact. We place this contact on the rear side because of its otherwise strong parasitic absorption. The Al-p+ contacts are also located at the rear side to avoid front-side shading. This results in a POLO-IBC cell structure. The efficiency of the best cell so far is 23.0% with a designated area of 4 cm2 fabricated on a M2-sized wafer. Scanning electron microscopy reveals an Al-p+ thickness of less than 3.3 μm and only a few 100 nm at the contact ends, which is less than the 5 μm typically for optimized Al-p+ contacts. A comparison of measured and simulated current-voltage curves over a variation of the contact fraction extracts a high saturation current density of the Al-p+ contact of J0-Al -p+ = 2,250 fA cm−2 for the current screen-print conditions and Al-paste causing an absolute efficiency loss of 0.5%abs. The recombination at the AlOx/SiNy surface and the shunt resistance limits the cell by 0.6%abs each.}, keywords = {IBC solar cells, local Al-p+, passivating contacts, POLO}, pubstate = {forthcoming}, tppubtype = {article} } Abstract We demonstrate the fabrication of a fully screen-printed p-type silicon solar cell with local hole-collecting Al-alloyed (Al-p+) contacts with a record open circuit voltage of 716 mV. The solar cell is fabricated by using almost the same process equipment as PERC cells. One of the dominant recombination losses in PERC cells is the recombination in the passivated and in the contacted emitter regions that so far limit the open circuit voltage to values below 700 mV. We eliminate these loss channels by substituting the P-diffused emitter by a passivating n-type poly-Silicon on Oxide (nPOLO) contact. We place this contact on the rear side because of its otherwise strong parasitic absorption. The Al-p+ contacts are also located at the rear side to avoid front-side shading. This results in a POLO-IBC cell structure. The efficiency of the best cell so far is 23.0% with a designated area of 4 cm2 fabricated on a M2-sized wafer. Scanning electron microscopy reveals an Al-p+ thickness of less than 3.3 μm and only a few 100 nm at the contact ends, which is less than the 5 μm typically for optimized Al-p+ contacts. A comparison of measured and simulated current-voltage curves over a variation of the contact fraction extracts a high saturation current density of the Al-p+ contact of J0-Al -p+ = 2,250 fA cm−2 for the current screen-print conditions and Al-paste causing an absolute efficiency loss of 0.5%abs. The recombination at the AlOx/SiNy surface and the shunt resistance limits the cell by 0.6%abs each.
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C. Xu, F. Heinemeyer, A. Dittrich, C. Bäumer, and R. Reineke-Koch AIP Advances 11 (3), 035126, (2021). Abstract | Links | BibTeX | Schlagwörter: Amorphous materials, Crystal structure, Magnetron sputtering, Optical metrology, Phase transitions, Stoichiometry, X-ray diffraction, X-ray photoelectron spectroscopy @article{Xu2021,
title = {In situ spectroscopic ellipsometry as a pathway toward achieving VO2 stoichiometry for amorphous vanadium oxide with magnetron sputtering}, author = {C Xu and F Heinemeyer and A Dittrich and C Bäumer and R Reineke-Koch}, doi = {10.1063/5.0041116}, year = {2021}, date = {2021-03-01}, journal = {AIP Advances}, volume = {11}, number = {3}, pages = {035126}, abstract = {As a special class of materials, transition metal oxides exhibit in their crystalline phase a variety of interesting properties, such as metal–insulator transition, ferroelectricity, magnetism, superconductivity, and so forth. However, for industrially widely applied methods such as room temperature magnetron sputtering, during initial fabrication steps of these materials, they are mostly amorphous, and control of stoichiometry during fabrication is challenging. It is, therefore, of pivotal importance to control the stoichiometry of transition metal oxides during growth in the amorphous state. One particularly important example for the necessity of stoichiometry control is vanadium dioxide (VO2), where small deviations in stoichiometry during fabrication result in unfavorable changes in the electronic and structural properties, for example, the metal–insulator transition temperature and optical permittivity. In this work, the stoichiometry of amorphous vanadium oxides is adjusted to VO2 using in situ spectroscopic ellipsometry (in situ SE) and verified by x-ray photoelectron spectroscopy. After an annealing process, a monoclinic VO2 crystalline structure is observed through x-ray diffraction at 30 °C. At an elevated temperature of 150 °C, which is higher than the typical metal–insulator transition temperature in VO2 of around 67 °C, a rutile crystalline structure is observed, which verifies the correctness of the stoichiometry of VO2. A Mott metal–insulator transition is revealed by the change in the imaginary part of optical permittivity through SE as well. Part of the presented work was funded by the German Federal Ministry for Economic Affairs and Energy, under Contract No. 0325858 A and B in accordance with a decision of the German Federal Parliament. This project was carried out in cooperation with the company Viessmann Werke GmbH and Co. KG. We thank Professor Regina Dittmann for scientific discussions and access to the electronic-oxide-UHV-cluster-tool at Forschungszentrum Jülich.}, keywords = {Amorphous materials, Crystal structure, Magnetron sputtering, Optical metrology, Phase transitions, Stoichiometry, X-ray diffraction, X-ray photoelectron spectroscopy}, pubstate = {published}, tppubtype = {article} } As a special class of materials, transition metal oxides exhibit in their crystalline phase a variety of interesting properties, such as metal–insulator transition, ferroelectricity, magnetism, superconductivity, and so forth. However, for industrially widely applied methods such as room temperature magnetron sputtering, during initial fabrication steps of these materials, they are mostly amorphous, and control of stoichiometry during fabrication is challenging. It is, therefore, of pivotal importance to control the stoichiometry of transition metal oxides during growth in the amorphous state. One particularly important example for the necessity of stoichiometry control is vanadium dioxide (VO2), where small deviations in stoichiometry during fabrication result in unfavorable changes in the electronic and structural properties, for example, the metal–insulator transition temperature and optical permittivity. In this work, the stoichiometry of amorphous vanadium oxides is adjusted to VO2 using in situ spectroscopic ellipsometry (in situ SE) and verified by x-ray photoelectron spectroscopy. After an annealing process, a monoclinic VO2 crystalline structure is observed through x-ray diffraction at 30 °C. At an elevated temperature of 150 °C, which is higher than the typical metal–insulator transition temperature in VO2 of around 67 °C, a rutile crystalline structure is observed, which verifies the correctness of the stoichiometry of VO2. A Mott metal–insulator transition is revealed by the change in the imaginary part of optical permittivity through SE as well.
Part of the presented work was funded by the German Federal Ministry for Economic Affairs and Energy, under Contract No. 0325858 A and B in accordance with a decision of the German Federal Parliament. This project was carried out in cooperation with the company Viessmann Werke GmbH and Co. KG. We thank Professor Regina Dittmann for scientific discussions and access to the electronic-oxide-UHV-cluster-tool at Forschungszentrum Jülich. |
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R. Eismann, S. Hummel, and F. Giovannetti Energies 14 (3), 733, (2021), ISSN: 1996-1073. Abstract | Links | BibTeX | Schlagwörter: stagnation @article{Eismann2021,
title = {A Thermal-Hydraulic Model for the Stagnation of Solar Thermal Systems with Flat-Plate Collector Arrays}, author = {R Eismann and S Hummel and F Giovannetti}, doi = {10.3390/en14030733}, issn = {1996-1073}, year = {2021}, date = {2021-02-01}, journal = {Energies}, volume = {14}, number = {3}, pages = {733}, abstract = {Stagnation is the transient state of a solar thermal system under high solar irradiation where the useful solar gain is zero. Both flat-plate collectors with selective absorber coatings and vacuum-tube collectors exhibit stagnation temperatures far above the saturation temperature of the glycol-based heat carriers within the range of typical system pressures. Therefore, stagnation is always associated with vaporization and propagation of vapor into the pipes of the solar circuit. It is therefore essential to design the system in such a way that vapor never reaches components that cannot withstand high temperatures. In this article, a thermal-hydraulic model based on the integral form of a two-phase mixture model and a drift-flux correlation is presented. The model is applicable to solar thermal flat-plate collectors with meander-shaped absorber tubes and selective absorber coatings. Experimental data from stagnation experiments on two systems, which are identical except for the optical properties of the absorber coating, allowed comparison with simulations carried out under the same boundary conditions. The absorber of one system features a conventional highly selective coating, while the absorber of the other system features a thermochromic coating, which exhibits a significantly lower stagnation temperature. Comparison of simulation results and experimental data shows good conformity. This model is implemented into an open-source software tool called THD for the thermal-hydraulic dimensioning of solar systems. The latest version of THD, updated by the results of this article, enables planners to achieve cost-optimal design of solar thermal systems and to ensure failsafe operation by predicting the steam range under the initial and boundary conditions of worst-case scenarios.}, keywords = {stagnation}, pubstate = {published}, tppubtype = {article} } Stagnation is the transient state of a solar thermal system under high solar irradiation where the useful solar gain is zero. Both flat-plate collectors with selective absorber coatings and vacuum-tube collectors exhibit stagnation temperatures far above the saturation temperature of the glycol-based heat carriers within the range of typical system pressures. Therefore, stagnation is always associated with vaporization and propagation of vapor into the pipes of the solar circuit. It is therefore essential to design the system in such a way that vapor never reaches components that cannot withstand high temperatures. In this article, a thermal-hydraulic model based on the integral form of a two-phase mixture model and a drift-flux correlation is presented. The model is applicable to solar thermal flat-plate collectors with meander-shaped absorber tubes and selective absorber coatings. Experimental data from stagnation experiments on two systems, which are identical except for the optical properties of the absorber coating, allowed comparison with simulations carried out under the same boundary conditions. The absorber of one system features a conventional highly selective coating, while the absorber of the other system features a thermochromic coating, which exhibits a significantly lower stagnation temperature. Comparison of simulation results and experimental data shows good conformity. This model is implemented into an open-source software tool called THD for the thermal-hydraulic dimensioning of solar systems. The latest version of THD, updated by the results of this article, enables planners to achieve cost-optimal design of solar thermal systems and to ensure failsafe operation by predicting the steam range under the initial and boundary conditions of worst-case scenarios.
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C. N. Kruse, S. Schäfer, F. Haase, V. Mertens, H. Schulte-Huxel, B. Lim, B. Min, T. Dullweber, R. Peibst, and R. Brendel Scientific Reports 11 (1), 996, (2021), ISSN: 2045-2322. Abstract | Links | BibTeX | Schlagwörter: POLO @article{Kruse2021,
title = {Simulation-based roadmap for the integration of poly-silicon on oxide contacts into screen-printed crystalline silicon solar cells}, author = {C N Kruse and S Schäfer and F Haase and V Mertens and H Schulte-Huxel and B Lim and B Min and T Dullweber and R Peibst and R Brendel}, doi = {10.1038/s41598-020-79591-6}, issn = {2045-2322}, year = {2021}, date = {2021-01-13}, journal = {Scientific Reports}, volume = {11}, number = {1}, pages = {996}, abstract = {We present a simulation-based study for identifying promising cell structures, which integrate poly-Si on oxide junctions into industrial crystalline silicon solar cells. The simulations use best-case measured input parameters to determine efficiency potentials. We also discuss the main challenges of industrially processing these structures. We find that structures based on p-type wafers in which the phosphorus diffusion is replaced by an n-type poly-Si on oxide junction (POLO) in combination with the conventional screen-printed and fired Al contacts show a high efficiency potential. The efficiency gains in comparsion to the 23.7% efficiency simulated for the PERC reference case are 1.0% for the POLO BJ (back junction) structure and 1.8% for the POLO IBC (interdigitated back contact) structure. The POLO BJ and the POLO IBC cells can be processed with lean process flows, which are built on major steps of the PERC process such as the screen-printed Al contacts and the $$backslashtextAl_backslashtext2 backslashtextO_backslashtext3 /backslashtextSiN $$Al2O3/SiNpassivation. Cell concepts with contacts using poly-Si for both polarities ($$backslashtextPOLO^2$$POLO2-concepts) show an even higher efficiency gain potential of 1.3% for a $$backslashtextPOLO^2$$POLO2BJ cell and 2.2% for a $$backslashtextPOLO^2$$POLO2IBC cell in comparison to PERC. For these structures further research on poly-Si structuring and screen-printing on p-type poly-Si is necessary.}, keywords = {POLO}, pubstate = {published}, tppubtype = {article} } We present a simulation-based study for identifying promising cell structures, which integrate poly-Si on oxide junctions into industrial crystalline silicon solar cells. The simulations use best-case measured input parameters to determine efficiency potentials. We also discuss the main challenges of industrially processing these structures. We find that structures based on p-type wafers in which the phosphorus diffusion is replaced by an n-type poly-Si on oxide junction (POLO) in combination with the conventional screen-printed and fired Al contacts show a high efficiency potential. The efficiency gains in comparsion to the 23.7% efficiency simulated for the PERC reference case are 1.0% for the POLO BJ (back junction) structure and 1.8% for the POLO IBC (interdigitated back contact) structure. The POLO BJ and the POLO IBC cells can be processed with lean process flows, which are built on major steps of the PERC process such as the screen-printed Al contacts and the $$backslashtextAl_backslashtext2 backslashtextO_backslashtext3 /backslashtextSiN $$Al2O3/SiNpassivation. Cell concepts with contacts using poly-Si for both polarities ($$backslashtextPOLO^2$$POLO2-concepts) show an even higher efficiency gain potential of 1.3% for a $$backslashtextPOLO^2$$POLO2BJ cell and 2.2% for a $$backslashtextPOLO^2$$POLO2IBC cell in comparison to PERC. For these structures further research on poly-Si structuring and screen-printing on p-type poly-Si is necessary.
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R. Witteck, S. Blankemeyer, M. Siebert, M. Köntges, and H. Schulte-Huxel Partial shading of one solar cell in a photovoltaic module with 3-terminal cell interconnection Artikel Solar Energy Materials and Solar Cells 219 , 110811, (2021), ISSN: 0927-0248. Abstract | Links | BibTeX | Schlagwörter: 3-terminal solar cell, PV module reliability, Solar module interconnection @article{Witteck2021b,
title = {Partial shading of one solar cell in a photovoltaic module with 3-terminal cell interconnection}, author = {R Witteck and S Blankemeyer and M Siebert and M Köntges and H Schulte-Huxel}, doi = {10.1016/j.solmat.2020.110811}, issn = {0927-0248}, year = {2021}, date = {2021-01-01}, journal = {Solar Energy Materials and Solar Cells}, volume = {219}, pages = {110811}, abstract = {We examine the electrical and thermal characteristics of a photovoltaic module with three-terminal cell interconnection when partially shading a solar cell by experimentally verified modeling. For the interconnection of multi junction and tandem solar cells a two- (2T), three- (3T), and four-terminal (4T) cell architecture is conceivable. The 3T architecture featuring a combination of parallel and series interconnection combines the advantageous of 2T and 4T cells without their drawbacks. We build a photovoltaic (PV) module with silicon solar cells in a 3T tandem solar cell interconnection configuration (3TTSC PV module) to emulate a solar module with 20 3TTSC. To the best of our knowledge, no 3TTSC PV module with more than five solar cells has been shown in previous studies. We measure the effect of partially shading a 3TTSC in this module and develop an electrical simulation to model our experimental results. In the simulations we determine the dissipated power in the top and bottom cells due to the current mismatch caused by partial shading. Our results reveal that the shaded top and bottom cell as well as the adjacent top cell dissipate power when a single 3TTSC is shaded. The two top cells share the dissipated power. Our simulated power dissipation correlates with temperature measurements of the 3TTSC PV module in a steady-state sun simulator. Therefore, in a 3TTSC PV module the temperature of a shaded cell is lower than in a module with 2T configuration. This is an advantage of PV modules with 3T tandem solar cells in terms of reliability and long-term stability.}, keywords = {3-terminal solar cell, PV module reliability, Solar module interconnection}, pubstate = {published}, tppubtype = {article} } We examine the electrical and thermal characteristics of a photovoltaic module with three-terminal cell interconnection when partially shading a solar cell by experimentally verified modeling. For the interconnection of multi junction and tandem solar cells a two- (2T), three- (3T), and four-terminal (4T) cell architecture is conceivable. The 3T architecture featuring a combination of parallel and series interconnection combines the advantageous of 2T and 4T cells without their drawbacks. We build a photovoltaic (PV) module with silicon solar cells in a 3T tandem solar cell interconnection configuration (3TTSC PV module) to emulate a solar module with 20 3TTSC. To the best of our knowledge, no 3TTSC PV module with more than five solar cells has been shown in previous studies. We measure the effect of partially shading a 3TTSC in this module and develop an electrical simulation to model our experimental results. In the simulations we determine the dissipated power in the top and bottom cells due to the current mismatch caused by partial shading. Our results reveal that the shaded top and bottom cell as well as the adjacent top cell dissipate power when a single 3TTSC is shaded. The two top cells share the dissipated power. Our simulated power dissipation correlates with temperature measurements of the 3TTSC PV module in a steady-state sun simulator. Therefore, in a 3TTSC PV module the temperature of a shaded cell is lower than in a module with 2T configuration. This is an advantage of PV modules with 3T tandem solar cells in terms of reliability and long-term stability.
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K. Sporleder, M. Turek, N. Schüler, V. Naumann, D. Hevisov, C. Pöblau, S. Großer, H. Schulte-Huxel, J. Bauer, and C. Hagendorf Quick test for reversible and irreversible PID of bifacial PERC solar cells Artikel Solar Energy Materials and Solar Cells 219 , 110755, (2021), ISSN: 0927-0248. Abstract | Links | BibTeX | Schlagwörter: Bifacial PERC, crystalline silicon, PID Test, Potential-induced degradation, Silicon corrosion, Solar Cells @article{Sporleder2021b,
title = {Quick test for reversible and irreversible PID of bifacial PERC solar cells}, author = {K Sporleder and M Turek and N Schüler and V Naumann and D Hevisov and C Pöblau and S Großer and H Schulte-Huxel and J Bauer and C Hagendorf}, doi = {10.1016/j.solmat.2020.110755}, issn = {0927-0248}, year = {2021}, date = {2021-01-01}, journal = {Solar Energy Materials and Solar Cells}, volume = {219}, pages = {110755}, abstract = {High voltage stress at the rear side of bifacial PERC cells leads to severe power losses. In contrast to monofacial PERC solar cells, reversible de-polarization related potential induced degradation (PID-p) and irreversible corrosive potential induced degradation (PID-c) can occur. Our results show that a reliable assessment of the solar cells power losses requires a modified PID test method which includes illumination in addition to the high voltage stress test. Furthermore, a recovery step needs to be added to the test scheme to separate reversible PID-p contributions from irreversible PID-c damages. We show that both, the degree of degradation as well as the contributions of PID-p and PIC-c depend sensitively on the solar cell under consideration. Thus, we propose to include both illumination during PID stress as well as a recovery step in the PID test scheme for bifacial PERC cells. Additionally, we show that the most sensitive cell parameter for the detection of rear side PID is given by the rear side measurement of the short circuit current. Finally, we present results showing that a 0.1 sun illumination during this characterization step is sufficient for an assessment of the PID. Based on these results, we propose a test setup which combines the required stress test conditions with an in-situ tracking of the PID.}, keywords = {Bifacial PERC, crystalline silicon, PID Test, Potential-induced degradation, Silicon corrosion, Solar Cells}, pubstate = {published}, tppubtype = {article} } High voltage stress at the rear side of bifacial PERC cells leads to severe power losses. In contrast to monofacial PERC solar cells, reversible de-polarization related potential induced degradation (PID-p) and irreversible corrosive potential induced degradation (PID-c) can occur. Our results show that a reliable assessment of the solar cells power losses requires a modified PID test method which includes illumination in addition to the high voltage stress test. Furthermore, a recovery step needs to be added to the test scheme to separate reversible PID-p contributions from irreversible PID-c damages. We show that both, the degree of degradation as well as the contributions of PID-p and PIC-c depend sensitively on the solar cell under consideration. Thus, we propose to include both illumination during PID stress as well as a recovery step in the PID test scheme for bifacial PERC cells. Additionally, we show that the most sensitive cell parameter for the detection of rear side PID is given by the rear side measurement of the short circuit current. Finally, we present results showing that a 0.1 sun illumination during this characterization step is sufficient for an assessment of the PID. Based on these results, we propose a test setup which combines the required stress test conditions with an in-situ tracking of the PID.
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P. Jäger, V. Mertens, U. Baumann, and T. Dullweber IEEE Journal of Photovoltaics 11 (1), 50-57, (2021). Abstract | Links | BibTeX | Schlagwörter: Diffusion profile, emitter saturation current density, in situ oxidation, Phosphorus Diffusion, phosphosilicate glass, SiO2 growth @article{Jäger2020c,
title = {A Detailed Chemical Model for the Diffusion of Phosphorus Into the Silicon Wafer During POCl3 Diffusion}, author = {P Jäger and V Mertens and U Baumann and T Dullweber}, doi = {10.1109/JPHOTOV.2020.3038331}, year = {2021}, date = {2021-01-01}, journal = {IEEE Journal of Photovoltaics}, volume = {11}, number = {1}, pages = {50-57}, abstract = {The POCl 3 diffusion is the main technology to form the p-n junction of industrial silicon solar cells. However, the diffusion mechanism of phosphorus (P) into the silicon wafer is not fully understood. In this article, we study the P diffusion mechanism during drive-in by systematically varying the drive-in time in the oxygen (O 2 ) atmosphere and subsequently in nitrogen (N 2 ). When increasing the drive-in time in O 2 from 0 to 120 min, the sheet resistance R sheet stays constant at 485±30 Ω/sq. Hence, we demonstrate for the first time that the phosphorus diffusion can be completely suppressed in the O 2 atmosphere. When adding a drive-in in the N 2 atmosphere directly after the drive-in in O 2 , we find that the SiO 2 thickness d SiO2,O2 changes from initially 2 to 10 nm after O 2 drive-in to an equilibrium SiO 2 thickness d SiO2,eq of 4.7 nm after N 2 drive-in. We prove for the first time that if d SiO2,O2 > d SiO2,eq , no P diffuses into the silicon wafer even in the N 2 atmosphere. Only if d SiO2,O2 < d SiO2,eq , phosphorus diffuses into the silicon wafer in the N 2 atmosphere. We propose a detailed chemical model to explain our experimental results, which assumes that the diffusion of Si from the wafer through the SiO 2 interface toward the PSG plays a key role. In this model, P can only diffuse into the Si wafer if P 2 O 5 in the PSG is reduced by the Si from the wafer to P and SiO 2 .}, keywords = {Diffusion profile, emitter saturation current density, in situ oxidation, Phosphorus Diffusion, phosphosilicate glass, SiO2 growth}, pubstate = {published}, tppubtype = {article} } The POCl 3 diffusion is the main technology to form the p-n junction of industrial silicon solar cells. However, the diffusion mechanism of phosphorus (P) into the silicon wafer is not fully understood. In this article, we study the P diffusion mechanism during drive-in by systematically varying the drive-in time in the oxygen (O 2 ) atmosphere and subsequently in nitrogen (N 2 ). When increasing the drive-in time in O 2 from 0 to 120 min, the sheet resistance R sheet stays constant at 485±30 Ω/sq. Hence, we demonstrate for the first time that the phosphorus diffusion can be completely suppressed in the O 2 atmosphere. When adding a drive-in in the N 2 atmosphere directly after the drive-in in O 2 , we find that the SiO 2 thickness d SiO2,O2 changes from initially 2 to 10 nm after O 2 drive-in to an equilibrium SiO 2 thickness d SiO2,eq of 4.7 nm after N 2 drive-in. We prove for the first time that if d SiO2,O2 > d SiO2,eq , no P diffuses into the silicon wafer even in the N 2 atmosphere. Only if d SiO2,O2 < d SiO2,eq , phosphorus diffuses into the silicon wafer in the N 2 atmosphere. We propose a detailed chemical model to explain our experimental results, which assumes that the diffusion of Si from the wafer through the SiO 2 interface toward the PSG plays a key role. In this model, P can only diffuse into the Si wafer if P 2 O 5 in the PSG is reduced by the Si from the wafer to P and SiO 2 .
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B. Min, N. Wehmeier, T. Brendemuehl, F. Haase, Y. Larionova, L. Nasebandt, H. Schulte-Huxel, R. Peibst, and R. Brendel Solar RRL 5 (1), 2000703, (2021). Abstract | Links | BibTeX | Schlagwörter: back junction, metallization, passivating contacts, polysilicon, screen-printing @article{https://doi.org/10.1002/solr.202000703b,
title = {716 mV Open-Circuit Voltage with Fully Screen-Printed p-Type Back Junction Solar Cells Featuring an Aluminum Front Grid and a Passivating Polysilicon on Oxide Contact at the Rear Side}, author = {B Min and N Wehmeier and T Brendemuehl and F Haase and Y Larionova and L Nasebandt and H Schulte-Huxel and R Peibst and R Brendel}, doi = {10.1002/solr.202000703}, year = {2021}, date = {2021-01-01}, journal = {Solar RRL}, volume = {5}, number = {1}, pages = {2000703}, abstract = {This article reports the recent progress of p-type back junction solar cells featuring an aluminum front grid and an n+-type passivating polysilicon on oxide (POLO) contact at the cell rear side. The best cell has an efficiency of 22.6% and an open-circuit voltage of 716 mV, independently confirmed by Institute for Solar Energy Research Hamelin (ISFH) CalTeC. The cell area is 244.5 cm2. The increase in the SiNx capping layer thickness at the cell rear side reduces the deterioration of passivation quality of the POLO contact by screen-printed silver. This increases the open-circuit voltage by 22 mV compared with cells with a thinner nitride layer thickness. The investigation with scanning electron microscopy shows that the damage of the POLO contacts underneath the screen-printed metal contacts is avoided by increasing the SiNx capping layer thickness. A contact resistivity of 2 mΩ cm2 is measured using the transfer length method.}, keywords = {back junction, metallization, passivating contacts, polysilicon, screen-printing}, pubstate = {published}, tppubtype = {article} } This article reports the recent progress of p-type back junction solar cells featuring an aluminum front grid and an n+-type passivating polysilicon on oxide (POLO) contact at the cell rear side. The best cell has an efficiency of 22.6% and an open-circuit voltage of 716 mV, independently confirmed by Institute for Solar Energy Research Hamelin (ISFH) CalTeC. The cell area is 244.5 cm2. The increase in the SiNx capping layer thickness at the cell rear side reduces the deterioration of passivation quality of the POLO contact by screen-printed silver. This increases the open-circuit voltage by 22 mV compared with cells with a thinner nitride layer thickness. The investigation with scanning electron microscopy shows that the damage of the POLO contacts underneath the screen-printed metal contacts is avoided by increasing the SiNx capping layer thickness. A contact resistivity of 2 mΩ cm2 is measured using the transfer length method.
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T. Gewohn, M. R. Vogt, B. Lim, C. Schinke, and R. Brendel Postproduction Coloring of Photovoltaic Modules With Imprinted Textiles Artikel IEEE Journal of Photovoltaics 11 (1), 138-143, (2021). Abstract | Links | BibTeX | Schlagwörter: Building integrated PV, colored BIPV @article{Gewohn2021,
title = {Postproduction Coloring of Photovoltaic Modules With Imprinted Textiles}, author = {T Gewohn and M R Vogt and B Lim and C Schinke and R Brendel}, doi = {10.1109/JPHOTOV.2020.3034001}, year = {2021}, date = {2021-01-01}, journal = {IEEE Journal of Photovoltaics}, volume = {11}, number = {1}, pages = {138-143}, abstract = {We present a customizable and potentially cost-efficient technique of coloring photovoltaic modules by laminating colored textiles onto photovoltaic cover glass (CoTex). A white nonwoven fabric is imprinted with any color, design, or graphic and is then laminated onto an arbitrary, frameless photovoltaic module. The short-circuit current losses of these modules range from 12% to 32% and depend on the type and coverage of the color, i.e., how much of the solar cell structure remains visible. Uncolored fabrics generate a grayish photovoltaic module with a short-circuit current density loss of 11% relative to a standard module. We fabricate CoTex building-integrated photovoltaic test modules and experimentally analyze their durability, UV stability, energy yield, hiding of the solar cells and appearance.}, keywords = {Building integrated PV, colored BIPV}, pubstate = {published}, tppubtype = {article} } We present a customizable and potentially cost-efficient technique of coloring photovoltaic modules by laminating colored textiles onto photovoltaic cover glass (CoTex). A white nonwoven fabric is imprinted with any color, design, or graphic and is then laminated onto an arbitrary, frameless photovoltaic module. The short-circuit current losses of these modules range from 12% to 32% and depend on the type and coverage of the color, i.e., how much of the solar cell structure remains visible. Uncolored fabrics generate a grayish photovoltaic module with a short-circuit current density loss of 11% relative to a standard module. We fabricate CoTex building-integrated photovoltaic test modules and experimentally analyze their durability, UV stability, energy yield, hiding of the solar cells and appearance.
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G. M. Wilson, M. M. Al-Jassim, W. K. Metzger, S. W. Glunz, P. Verlinden, X. Gang, L. M. Mansfield, B. J. Stanbery, K. Zhu, Y. Yan, J. J. Berry, A. J. Ptak, F. Dimroth, B. M. Kayes, A. C. Tamboli, R. Peibst, K. R. Catchpole, M. Reese, C. Klinga, P. Denholm, M. Morjaria, M. G. Deceglie, J. M. Freeman, M. A. Mikofski, D. C. Jordan, G. TamizhMani, and D. B. Sulas The 2020 Photovoltaic Technologies Roadmap Artikel Journal of Physics D: Applied Physics 53 (49), 493001, (2020). Abstract | Links | BibTeX | Schlagwörter: solar @article{Wilson2020,
title = {The 2020 Photovoltaic Technologies Roadmap}, author = {G M Wilson and M M Al-Jassim and W K Metzger and S W Glunz and P Verlinden and X Gang and L M Mansfield and B J Stanbery and K Zhu and Y Yan and J J Berry and A J Ptak and F Dimroth and B M Kayes and A C Tamboli and R Peibst and K R Catchpole and M Reese and C Klinga and P Denholm and M Morjaria and M G Deceglie and J M Freeman and M A Mikofski and D C Jordan and G TamizhMani and D B Sulas}, doi = {10.1088/1361-6463/ab9c6a}, year = {2020}, date = {2020-12-02}, journal = {Journal of Physics D: Applied Physics}, volume = {53}, number = {49}, pages = {493001}, abstract = {Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years.}, keywords = {solar}, pubstate = {published}, tppubtype = {article} } Over the past decade, the global cumulative installed photovoltaic (PV) capacity has grown exponentially, reaching 591 GW in 2019. Rapid progress was driven in large part by improvements in solar cell and module efficiencies, reduction in manufacturing costs and the realization of levelized costs of electricity that are now generally less than other energy sources and approaching similar costs with storage included. Given this success, it is a particularly fitting time to assess the state of the photovoltaics field and the technology milestones that must be achieved to maximize future impact and forward momentum. This roadmap outlines the critical areas of development in all of the major PV conversion technologies, advances needed to enable terawatt-scale PV installation, and cross-cutting topics on reliability, characterization, and applications. Each perspective provides a status update, summarizes the limiting immediate and long-term technical challenges and highlights breakthroughs that are needed to address them. In total, this roadmap is intended to guide researchers, funding agencies and industry in identifying the areas of development that will have the most impact on PV technology in the upcoming years.
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L. Helmich, D. C. Walter, D. Bredemeier, and J. Schmidt physica status solidi (RRL) – Rapid Research Letters 14 (12), 2000367, (2020). Abstract | Links | BibTeX | Schlagwörter: Aluminum oxide, defects, diffusion, Hydrogen, silicon @article{Helmich2020,
title = {Atomic-Layer-Deposited Al2O3 as Effective Barrier against the Diffusion of Hydrogen from SiNx:H Layers into Crystalline Silicon during Rapid Thermal Annealing}, author = {L Helmich and D C Walter and D Bredemeier and J Schmidt}, doi = {10.1002/pssr.202000367}, year = {2020}, date = {2020-12-01}, journal = {physica status solidi (RRL) – Rapid Research Letters}, volume = {14}, number = {12}, pages = {2000367}, abstract = {Stacks of hydrogen-lean aluminum oxide, deposited via plasma-assisted atomic-layer-deposition, and hydrogen-rich plasma-enhanced chemical vapor-deposited silicon nitride (SiNx) are applied to boron-doped float-zone silicon wafers. A rapid thermal annealing (RTA) step is performed in an infrared conveyor-belt furnace at different set-peak temperatures. The hydrogen content diffused into the crystalline silicon during the RTA step is quantified by measurements of the silicon resistivity increase due to hydrogen passivation of boron dopant atoms. These experiments indicate that there exists a temperature-dependent maximum in the introduced hydrogen content. The exact position of this maximum depends on the composition of the SiNx layer. The highest total hydrogen content, exceeding 1015 cm−3, is introduced into the silicon bulk from silicon-rich SiNx layers with a refractive index of 2.3 (at λ = 633 nm) at an RTA peak temperature of 800 °C, omitting the Al2O3 interlayer. Adding an Al2O3 interlayer with a thickness of 20 nm reduces the hydrogen content by a factor of four, demonstrating that Al2O3 acts as a highly effective hydrogen diffusion barrier. Measuring the hydrogen content in the silicon bulk as a function of Al2O3 thickness at different RTA peak temperatures provides the hydrogen diffusion length in Al2O3 as a function of measured temperature.}, keywords = {Aluminum oxide, defects, diffusion, Hydrogen, silicon}, pubstate = {published}, tppubtype = {article} } Stacks of hydrogen-lean aluminum oxide, deposited via plasma-assisted atomic-layer-deposition, and hydrogen-rich plasma-enhanced chemical vapor-deposited silicon nitride (SiNx) are applied to boron-doped float-zone silicon wafers. A rapid thermal annealing (RTA) step is performed in an infrared conveyor-belt furnace at different set-peak temperatures. The hydrogen content diffused into the crystalline silicon during the RTA step is quantified by measurements of the silicon resistivity increase due to hydrogen passivation of boron dopant atoms. These experiments indicate that there exists a temperature-dependent maximum in the introduced hydrogen content. The exact position of this maximum depends on the composition of the SiNx layer. The highest total hydrogen content, exceeding 1015 cm−3, is introduced into the silicon bulk from silicon-rich SiNx layers with a refractive index of 2.3 (at λ = 633 nm) at an RTA peak temperature of 800 °C, omitting the Al2O3 interlayer. Adding an Al2O3 interlayer with a thickness of 20 nm reduces the hydrogen content by a factor of four, demonstrating that Al2O3 acts as a highly effective hydrogen diffusion barrier. Measuring the hydrogen content in the silicon bulk as a function of Al2O3 thickness at different RTA peak temperatures provides the hydrogen diffusion length in Al2O3 as a function of measured temperature.
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B. Min, N. Wehmeier, T. Brendemuehl, A. Merkle, F. Haase, Y. Larionova, L. David, H. Schulte-Huxel, R. Peibst, and R. Brendel Solar RRL 4 (12), 2000435, (2020). Abstract | Links | BibTeX | Schlagwörter: back junction, p-type wafers, polycrystalline passivating contacts @article{Min2020b,
title = {A 22.3% Efficient p-Type Back Junction Solar Cell with an Al-Printed Front-Side Grid and a Passivating n+-Type Polysilicon on Oxide Contact at the Rear Side}, author = {B Min and N Wehmeier and T Brendemuehl and A Merkle and F Haase and Y Larionova and L David and H Schulte-Huxel and R Peibst and R Brendel}, doi = {10.1002/solr.202000435}, year = {2020}, date = {2020-12-01}, journal = {Solar RRL}, volume = {4}, number = {12}, pages = {2000435}, abstract = {The fabrication of a silicon solar cell on 6 in. pseudo-square p-type Czochralski grown silicon wafers featuring poly-Si-based passivating contacts for electrons at the cell rear side and screen-printed aluminum fingers at the front side is demonstrated. The undiffused front surface is passivated with an Al2O3/SiNx stack, and the rear surface is covered with a thin oxide/n+-poly-Si/Al2O3/SiNx layer system, contacted by screen-printed silver fingers. A loss analysis shows that the recombination losses at the metal contacts on both cell sides dominate the total energy losses. A voltage of 700 mV as the highest open-circuit voltage from a batch of seven cells is achieved, and the best cell efficiency is 22.3%, independently confirmed.}, keywords = {back junction, p-type wafers, polycrystalline passivating contacts}, pubstate = {published}, tppubtype = {article} } The fabrication of a silicon solar cell on 6 in. pseudo-square p-type Czochralski grown silicon wafers featuring poly-Si-based passivating contacts for electrons at the cell rear side and screen-printed aluminum fingers at the front side is demonstrated. The undiffused front surface is passivated with an Al2O3/SiNx stack, and the rear surface is covered with a thin oxide/n+-poly-Si/Al2O3/SiNx layer system, contacted by screen-printed silver fingers. A loss analysis shows that the recombination losses at the metal contacts on both cell sides dominate the total energy losses. A voltage of 700 mV as the highest open-circuit voltage from a batch of seven cells is achieved, and the best cell efficiency is 22.3%, independently confirmed.
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N. Folchert, R. Peibst, and R. Brendel Modeling recombination and contact resistance of poly-Si junctions Artikel Progress in Photovoltaics: Research and Applications 28 (12), 1289-1307, (2020). Abstract | Links | BibTeX | Schlagwörter: carrier-selective-junction, Contact resistance, passivating contact, pinhole, POLO, Poly-Si, surface recombination, Tunneling @article{Folchert2020,
title = {Modeling recombination and contact resistance of poly-Si junctions}, author = {N Folchert and R Peibst and R Brendel}, doi = {10.1002/pip.3327}, year = {2020}, date = {2020-12-01}, journal = {Progress in Photovoltaics: Research and Applications}, volume = {28}, number = {12}, pages = {1289-1307}, abstract = {We present a semi-analytical model for the calculation of the current through and the recombination in carrier-selective junctions consisting of a poly-Si/SiOx/c-Si layer stack. We calculate the recombination parameter J0 and the contact resistance ρC after solving the band-bending-problem on both sides of the interfacial oxide. Comparisons with finite-element simulations show that the current calculation is reliable at all bias conditions except for inversion and that current through pinholes is resolved adequately in the model. The model allows a coherent description of lifetime-, current-voltage- and capacitance-voltage measurements performed on a sample with dominant tunneling. We use our model to investigate the influence of oxide thickness and pinhole density on J0 and ρC of our state-of-the-art poly-silicon-on-oxide (POLO) junctions and demonstrate its usefulness for the optimization of poly-Si based junctions.}, keywords = {carrier-selective-junction, Contact resistance, passivating contact, pinhole, POLO, Poly-Si, surface recombination, Tunneling}, pubstate = {published}, tppubtype = {article} } We present a semi-analytical model for the calculation of the current through and the recombination in carrier-selective junctions consisting of a poly-Si/SiOx/c-Si layer stack. We calculate the recombination parameter J0 and the contact resistance ρC after solving the band-bending-problem on both sides of the interfacial oxide. Comparisons with finite-element simulations show that the current calculation is reliable at all bias conditions except for inversion and that current through pinholes is resolved adequately in the model. The model allows a coherent description of lifetime-, current-voltage- and capacitance-voltage measurements performed on a sample with dominant tunneling. We use our model to investigate the influence of oxide thickness and pinhole density on J0 and ρC of our state-of-the-art poly-silicon-on-oxide (POLO) junctions and demonstrate its usefulness for the optimization of poly-Si based junctions.
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R. Peibst, R. Brendel, F. Haase, C. Hollemann, C. Kruse, Y. Larionova, B. Lim, J. Krügener, B. Min, and M. Rienäcker Passivating poly-Si on oxide contacts – from fundamental investigations towards industrial implementation Presentation/Poster Online Event, 30.11.2020, (2nd International Conference on Photovoltaic Science and Technologies (PVCon2020)). @misc{Peibst2020b,
title = {Passivating poly-Si on oxide contacts – from fundamental investigations towards industrial implementation}, author = {R Peibst and R Brendel and F Haase and C Hollemann and C Kruse and Y Larionova and B Lim and J Krügener and B Min and M Rienäcker}, year = {2020}, date = {2020-11-30}, address = {Online Event}, note = {2nd International Conference on Photovoltaic Science and Technologies (PVCon2020)}, keywords = {POLO}, pubstate = {published}, tppubtype = {presentation} } |
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D. Büchner, O. Mercker, and K. Wurdinger OptDienE: Optionen zum netzdienlichen Betrieb von Einzelraumfeuerstätten Presentation/Poster Online Event, 24.11.2020, (Fachkonferenz Energetische Biomassenutzung (Gemeinsame Fachkonferenz der BMWi-Forschungsnetzwerke Bioenergie und Energiewendebauen)). BibTeX | Schlagwörter: netzdienlich @misc{Büchner2020,
title = {OptDienE: Optionen zum netzdienlichen Betrieb von Einzelraumfeuerstätten}, author = {D Büchner and O Mercker and K Wurdinger}, year = {2020}, date = {2020-11-24}, address = {Online Event}, note = {Fachkonferenz Energetische Biomassenutzung (Gemeinsame Fachkonferenz der BMWi-Forschungsnetzwerke Bioenergie und Energiewendebauen)}, keywords = {netzdienlich}, pubstate = {published}, tppubtype = {presentation} } |
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T. Ohrdes, E. Schneider, and M. Knoop Wind-Solar-Wärmepumpenquartier Presentation/Poster Online Event, 24.11.2020, (Fachkonferenz Energetische Biomassenutzung (Gemeinsame Fachkonferenz der BMWi-Forschungsnetzwerke Bioenergie und Energiewendebauen)). BibTeX | Schlagwörter: Quartier @misc{Ohrdes2020f,
title = {Wind-Solar-Wärmepumpenquartier}, author = {T Ohrdes and E Schneider and M Knoop}, year = {2020}, date = {2020-11-24}, address = {Online Event}, note = {Fachkonferenz Energetische Biomassenutzung (Gemeinsame Fachkonferenz der BMWi-Forschungsnetzwerke Bioenergie und Energiewendebauen)}, keywords = {Quartier}, pubstate = {published}, tppubtype = {presentation} } |
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B. Lim Form, color, function: R&D aspects of VIPV module technology Presentation/Poster Online Event, 18.11.2020, (ETIP-PV Virtual Conference 2020: I3PV – Integrated, Innovative, Intelligent). @misc{Lim2020b,
title = {Form, color, function: R&D aspects of VIPV module technology}, author = {B Lim}, year = {2020}, date = {2020-11-18}, address = {Online Event}, note = {ETIP-PV Virtual Conference 2020: I3PV – Integrated, Innovative, Intelligent}, keywords = {VIPV}, pubstate = {published}, tppubtype = {presentation} } |
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M. Yasin Automatisierte Effizienzkontrolle von Wärmezentralen in Mehrfamilienhäusern Presentation/Poster Online Event, 13.11.2020, (12. EffizienzTagung Bauen+Modernisieren). @misc{Yasin2020,
title = {Automatisierte Effizienzkontrolle von Wärmezentralen in Mehrfamilienhäusern}, author = {M Yasin}, year = {2020}, date = {2020-11-13}, address = {Online Event}, note = {12. EffizienzTagung Bauen+Modernisieren}, keywords = {MFH}, pubstate = {published}, tppubtype = {presentation} } |
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E. Schneider Wärmepumpenquartier mit Wind und PV Presentation/Poster Online Event, 12.11.2020, (Webinarreihe "Norddeutsche Wärme-Forschung"). @misc{Schneider2020b,
title = {Wärmepumpenquartier mit Wind und PV}, author = {E Schneider}, year = {2020}, date = {2020-11-12}, address = {Online Event}, note = {Webinarreihe "Norddeutsche Wärme-Forschung"}, keywords = {Wärme}, pubstate = {published}, tppubtype = {presentation} } |
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F. Hüsing Erdwärmekollektor und Solarregeneration im EFH Presentation/Poster Online Event, 12.11.2020, (Webinarreihe "Norddeutsche Wärme-Forschung"). @misc{Hüsing2020b,
title = {Erdwärmekollektor und Solarregeneration im EFH}, author = {F Hüsing}, year = {2020}, date = {2020-11-12}, address = {Online Event}, note = {Webinarreihe "Norddeutsche Wärme-Forschung"}, keywords = {Wärme}, pubstate = {published}, tppubtype = {presentation} } |
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F. Weiland Erdwärmesonden und Regeneration mit Metallfassaden im Fabrikgebäude Presentation/Poster Online Event, 12.11.2020, (Webinarreihe "Norddeutsche Wärme-Forschung"). @misc{Weiland2020c,
title = {Erdwärmesonden und Regeneration mit Metallfassaden im Fabrikgebäude}, author = {F Weiland}, year = {2020}, date = {2020-11-12}, address = {Online Event}, note = {Webinarreihe "Norddeutsche Wärme-Forschung"}, keywords = {Wärme}, pubstate = {published}, tppubtype = {presentation} } |
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B. Chhugani PVT als alleinige Wärmequelle für Einfamilienhäuser Presentation/Poster Online Event, 12.11.2020, (Webinarreihe "Norddeutsche Wärme-Forschung"). @misc{Chhugani2020c,
title = {PVT als alleinige Wärmequelle für Einfamilienhäuser}, author = {B Chhugani}, year = {2020}, date = {2020-11-12}, address = {Online Event}, note = {Webinarreihe "Norddeutsche Wärme-Forschung"}, keywords = {Wärme}, pubstate = {published}, tppubtype = {presentation} } |