C Gemmel; J Hensen; S Kajari-Schröder; R Brendel
In: IEEE Journal of Photovoltaics, Bd. 7, Nr. 2, S. 430-436, 2017, ISSN: 2156-3381.
@article{Gemmel2017,
title = {4.5 ms Effective Carrier Lifetime in Kerfless Epitaxial Silicon Wafers From the Porous Silicon Process},
author = {C Gemmel and J Hensen and S Kajari-Schröder and R Brendel},
doi = {10.1109/JPHOTOV.2016.2642640},
issn = {2156-3381},
year = {2017},
date = {2017-03-01},
journal = {IEEE Journal of Photovoltaics},
volume = {7},
number = {2},
pages = {430-436},
abstract = {Kerfless silicon wafers epitaxially grown on porous silicon (PSI) and subsequently detached from the growth substrate are a promising candidate for reducing the cost of the silicon wafer, which is particularly important for silicon photovoltaics. However, the carrier lifetime of these epitaxial wafers has to be at least as high as that of today's standard Czochralski (Cz)-grown wafers in order to become competitive. Here, we compare the measured lifetimes of n-type epitaxial silicon wafers that grow on PSI and epitaxial silicon wafers that grow on nonporous surfaces of epi-ready wafers. The latter are subsequently ground to have free-standing epitaxial wafers. Gettering improves the carrier lifetime of the ground wafers up to 4.2 ms. In contrast, PSI wafers show regions with effective lifetimes of 4.5 ms, even without gettering. This lifetime value is a factor of four larger than lifetimes of Cz wafers which are typically employed in today's PERC solar cells. We model the lifetime measurements with three Shockley-Read-Hall (SRH) defects: two defects that exist in the PSI and in the epi-ready wafer and a third defect that is only present in the epi-ready wafer.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
M R Vogt; H Schulte-Huxel; M Offer; S Blankemeyer; R Witteck; M Köntges; K Bothe; R Brendel
In: IEEE Journal of Photovoltaics, Bd. 7, Nr. 1, S. 44-50, 2017, ISSN: 2156-3381.
@article{Vogt2017b,
title = {Reduced module operating temperature and increased yield of modules with PERC instead of Al-BSF solar cells},
author = {M R Vogt and H Schulte-Huxel and M Offer and S Blankemeyer and R Witteck and M Köntges and K Bothe and R Brendel},
doi = {10.1109/JPHOTOV.2016.2616191},
issn = {2156-3381},
year = {2017},
date = {2017-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {7},
number = {1},
pages = {44-50},
abstract = {We demonstrate a reduced operating temperature of modules made from passivated emitter rear cells (PERCs) compared with modules made from cells featuring an unpassivated fullarea screen-printed aluminum rear side metallization aluminum back surface field (Al-BSF). Measurements on specific test modules fabricated from p-type silicon PERC and Al-BSF solar cells reveal a 4 °C lower operating temperature for the PERC module under 1400 W/m2 halogen illumination, if no temperature control is applied. For detailed analysis of the temperature effect, we perform a 3-D ray tracing analysis in the spectral range from 300 to 2500 nm to determine the radiative heat sources in a photovoltaic (PV) module. We combine these heat sources with a 1-D finite element method model solving the coupled system of semiconductor, thermal conduction, convection, and radiation equations for module temperature and power output. The simulations reveal that the origin of the reduced temperature of the PERC modules is a higher efficiency, as well as a higher reflectivity, of the cells rear side mirror. This reduces the parasitic absorptions in the rear metallization and increases the reflection for wavelengths above 1000 nm. This operating temperature difference is simulated to be linear in intensity. The slope depends on the spectral distribution of the incoming light. Under 1000 W/m2 in AM1.5G, our simulations reveal that the operating temperature difference is about 1.7 °C. The operating temperature can be lowered another 3.2 °C, if all parasitic absorption for wavelengths longer than 1200 nm can be prevented. Standard testing conditions applying a temperature control to the module do not show this effect of enhanced performance of the PERC modules. Yield calculations for systems in the field will thus systematically underestimate their electrical power output unless the inherently lower operating temperature of PERC modules is taken into account.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
J Krügener; D Tetzlaff; Y Larionova; Y Barnscheidt; S Reiter; M Turcu; R Peibst; J -D Kähler; T Wietler
Electrical deactivation of boron in p+-poly/SiOx/crystalline silicon passivating contacts for silicon solar cells Proceedings Article
In: IEEE, (Hrsg.): Proceedings of the 21st International Conference on Ion Implantation Technology (IIT), Tainan, Taiwan, 2016, ISBN: 978-1-5090-2025-6.
@inproceedings{Krügener2016,
title = {Electrical deactivation of boron in p+-poly/SiOx/crystalline silicon passivating contacts for silicon solar cells},
author = {J Krügener and D Tetzlaff and Y Larionova and Y Barnscheidt and S Reiter and M Turcu and R Peibst and J -D Kähler and T Wietler},
editor = {IEEE},
doi = {10.1109/IIT.2016.7882868},
isbn = {978-1-5090-2025-6},
year = {2016},
date = {2016-09-23},
booktitle = {Proceedings of the 21st International Conference on Ion Implantation Technology (IIT)},
journal = {Proceedings of the 21st International Conference on Ion Implantation Technology (IIT)},
address = {Tainan, Taiwan},
abstract = {Passivating junctions, like hole-collecting p+-polycrystalline silicon/SiOx/crystalline silicon junctions, need a thermal treatment to activate their excellent passivation and contact properties. Aside from surface passivation and from contact resistance between poly-Si and the substrate, the sheet resistance within the poly-Si is another important parameter for solar cell design. We present electrical investigations of in situ boron-doped (deposited by low pressure chemical vapor deposition) and ion-implanted (intrinsically deposited and subsequently ion-implanted with boron) p+-poly-Si/SiOx/c-Si stacks after annealing. We find electrical deactivation of boron after annealing which strongly depends on the total boron concentration and the subsequent annealing temperature.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
J Krügener; Y Larionova; B Wolpensinger; D Tetzlaff; S Reiter; M Turcu; R Peibst; J -D Kähler; T Wietler
Dopant diffusion from p+-poly-Si into c-Si during thermal annealing Proceedings Article
In: IEEE, (Hrsg.): 2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC), S. 2451-2454, Portland, OR, USA, 2016, ISBN: 978-1-5090-2725-5.
@inproceedings{Krügener2016bc,
title = {Dopant diffusion from p+-poly-Si into c-Si during thermal annealing},
author = {J Krügener and Y Larionova and B Wolpensinger and D Tetzlaff and S Reiter and M Turcu and R Peibst and J -D Kähler and T Wietler},
editor = {IEEE},
doi = {10.1109/PVSC.2016.7750083},
isbn = {978-1-5090-2725-5},
year = {2016},
date = {2016-06-01},
booktitle = {2016 IEEE 43rd Photovoltaic Specialists Conference (PVSC)},
journal = {Proceedings of the 43rd IEEE Photovoltaic Specialists Conference},
pages = {2451-2454},
address = {Portland, OR, USA},
abstract = {Passivating junctions, like hole-collecting p-polycrystalline silicon/SiOx/crystalline silicon junctions, need a thermal activation to activate their excellent passivation and contact properties. Here, the diffusion of boron from the highly doped poly-Si layer into the Si is often considered to compromise the passivation quality. In contrast we show that at least a slight diffusion of boron into the crystalline silicon is present for optimized annealing conditions. We achieve low emitter saturation current densities of 11 fA/cm2 for in situ p+ doped polysilicon deposited by low pressure chemical vapor deposition. Furthermore, we show that the polysilicon layer and the in-diffused region within the substrate are electrically connected.},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
J Krügener; R Peibst; F A Wolf; E Bugiel; T Ohrdes; F Kiefer; C Schöllhorn; A Grohe; R Brendel; H J Osten
In: IEEE Journal of Photovoltaics, Bd. 5, Nr. 1, S. 166-173, 2015.
@article{Krügener2015,
title = {Electrical and structural analysis of crystal defects after high-temperature rapid thermal annealing of highly boron ion-implanted emitters},
author = {J Krügener and R Peibst and F A Wolf and E Bugiel and T Ohrdes and F Kiefer and C Schöllhorn and A Grohe and R Brendel and H J Osten},
doi = {10.1109/JPHOTOV.2014.2365468},
year = {2015},
date = {2015-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {5},
number = {1},
pages = {166-173},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
J Müller; H Hannebauer; C Mader; F Haase; K Bothe
In: IEEE Journal of Photovoltaics, Bd. 4, Nr. 2, S. 540-548, 2014.
@article{Müller2014,
title = {Dynamic infrared lifetime mapping for the measurement of the saturation current density of highly doped regions in silicon},
author = {J Müller and H Hannebauer and C Mader and F Haase and K Bothe},
doi = {10.1109/JPHOTOV.2013.2293062},
year = {2014},
date = {2014-03-01},
journal = {IEEE Journal of Photovoltaics},
volume = {4},
number = {2},
pages = {540-548},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
C Mader; U Eitner; S Kajari-Schröder; R Brendel
Bow of Silicon Wafers After In-Line High-Rate Evaporation of Aluminum Artikel
In: IEEE Journal of Photovoltaics, Bd. 3, Nr. 1, S. 212-216, 2013.
@article{Mader2013,
title = {Bow of Silicon Wafers After In-Line High-Rate Evaporation of Aluminum},
author = {C Mader and U Eitner and S Kajari-Schröder and R Brendel},
doi = {10.1109/JPHOTOV.2012.2218578},
year = {2013},
date = {2013-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {3},
number = {1},
pages = {212-216},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
J D Murphy; K Bothe; R Krain; V V Voronkov; R J Falster
In: Journal of Applied Physics, Bd. 111, Nr. 11, S. 113709, 2012.
@article{Murphy2012,
title = {Parameterisation of injection-dependent lifetime measurements in semiconductors in terms of Shockley-Read-Hall statistics: An application to oxide precipitates in silicon,},
author = {J D Murphy and K Bothe and R Krain and V V Voronkov and R J Falster},
doi = {10.1063/1.4725475},
year = {2012},
date = {2012-06-01},
journal = {Journal of Applied Physics},
volume = {111},
number = {11},
pages = {113709},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
H Wagner; A Dastgheib-Shirazi; R Chen; S T Dunham; M Kessler; P P Altermatt
Improving the predictive power of modeling the emitter diffusion by fully including the phosphsilicate glass (PSG) layer Proceedings Article
In: IEEE, (Hrsg.): 2011 37th IEEE Photovoltaic Specialists Conference, S. 002957-002962, Seattle, WA, USA, 2011, ISSN: 0160-8371.
@inproceedings{Wagner2011,
title = {Improving the predictive power of modeling the emitter diffusion by fully including the phosphsilicate glass (PSG) layer},
author = {H Wagner and A Dastgheib-Shirazi and R Chen and S T Dunham and M Kessler and P P Altermatt},
editor = {IEEE},
doi = {10.1109/PVSC.2011.6186566},
issn = {0160-8371},
year = {2011},
date = {2011-06-01},
booktitle = {2011 37th IEEE Photovoltaic Specialists Conference},
pages = {002957-002962},
address = {Seattle, WA, USA},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}