@article{Schmidt2020,

title = {Fast and Slow Stages of Lifetime Degradation by Boron–Oxygen Centers in Crystalline Silicon},

author = {J Schmidt and K Bothe and V V Voronkov and R Falster},

doi = {10.1002/pssb.201900167},

year  = {2020},

date = {2020-01-01},

journal = {physica status solidi (b)},

volume = {257},

number = {1},

pages = {1900167},

abstract = {A conflict between previous and recently published data on the two-stage light-induced degradation (LID) of carrier lifetime in boron-doped oxygen-containing crystalline silicon is addressed. The previous experiments showed the activation of two boron–oxygen recombination centers with strongly differing recombination properties for the fast and slow stages of LID, whereas more recent studies found only a single center for both stages. To resolve this controversy, the historic silicon samples of these previous examinations are re-examined in this study after more than one decade. It is found that, in the historic samples, the fast stage can be either described by two different centers or a mixture of the two, depending on the duration of previous dark annealing. A possible solution is suggested based on the involvement of different activating impurities in the boron–oxygen defect. In dark-annealed samples, the defect consisting of boron, oxygen, and the activation impurity is present in two latent configurations, which reconfigure during LID at a fast and a slow stage. In the examined historic silicon samples, which did not undergo a gettering pretreatment, a significant concentration of an additional boron–oxygen defect with a different kind of activating impurity attached exists. The historic and modern results are thus reconciled.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Min2017d,

title = {Fundamental consideration of junction formation strategies for phosphorus-doped emitters with J0e < 10 fA/cm2},

author = {B Min and J Krügener and M Müller and K Bothe and R Brendel},

doi = {10.1016/j.egypro.2017.09.323},

issn = {1876-6102},

year  = {2017},

date = {2017-09-21},

journal = {Energy Procedia},

volume = {124},

number = {Supplement C},

pages = {126-130},

abstract = {This work shows the potential of further optimization of phosphorus-doped emitters in p-type silicon solar cells. We investigate the impact of different combinations of phosphorus doping profiles and surface passivation qualities on the saturation current density J0e by considering boundary conditions based on published experimental data. Our simulation study shows that there are two possible ways to achieve J0e values below 10 fA/cm2. One is the reduction of the electrically active phosphorus concentration nsurf at the surface beneath 2×10^19 cm−3 and simultaneously reducing the surface recombination velocity Sp to below 103 cm/s. The other contrarily increases nsurf to values of up to 1×10^21 cm−3 while ensuring full activation of all phosphorus dopants. In the latter case, J0e values below 10 fA/cm2 seem possible, even for Sp = 10^7 cm/s which is equal to the thermal velocity.},

note = {7th International Conference on Silicon Photovoltaics, SiliconPV 2017, 3-5 April 2017, Freiburg, Germany},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rienäcker2017b,

title = {Junction resistivity of carrier-selective polysilicon on oxide junctions and its impact on solar cell performance},

author = {M Rienäcker and M Bossmeyer and A Merkle and U Römer and F Haase and J Krügener and R Brendel and R Peibst},

doi = {10.1109/JPHOTOV.2016.2614123},

issn = {2156-3381},

year  = {2017},

date = {2017-01-01},

journal = {IEEE Journal of Photovoltaics},

volume = {7},

number = {1},

pages = {11-18},

abstract = {We investigate the junction resistivity of high-quality carrier-selective polysilicon on oxide (POLO) junctions with the transfer length method. We demonstrate n+ POLO junctions with a saturation current density JC,poly of 6.2 fA/cm2 and a junction resistivity ρc of 0.6 mΩcm2, counterdoped n+ POLO junctions with 2.7 fA/cm2 and 1.3 mΩcm2, and p+ POLO junctions with 6.7 fA/cm2 and 0.2 mΩcm2. Such low junction resistivities and saturation current densities correspond to excellent selectivities S10 of up to 16.2. The efficiency potential for back-junction back-contact solar cells with these POLO junctions was determined to be larger than 25 % by numerical device simulations. We demonstrate experimentally a back-junction back-contact solar cell with p-type and n-type POLO junctions with an independently confirmed efficiency of 24.25 %.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rienäcker2016c,

title = {Recombination Behavior of Photolithography-free Back Junction Back Contact Solar Cells with Carrier-selective Polysilicon on Oxide Junctions for Both Polarities},

author = {M Rienäcker and A Merkle and U Römer and H Kohlenberg and J Krügener and R Brendel and R Peibst},

doi = {10.1016/j.egypro.2016.07.121},

issn = {1876-6102},

year  = {2016},

date = {2016-08-01},

journal = {Energy Procedia},

volume = {92},

pages = {412-418},

abstract = {We report on ion-implanted, inkjet patterned back junction back contact silicon solar cells with POLysilicon on Oxide (POLO) junctions for both polarities – n+ doped BSF and p+ doped emitter. The recombination behavior is investigated at two different processing stages: before and after trench separation of p+ and n+ regions within polysilicon (poly-Si). Before trench separation, we find a systematic dependence of the recombination behavior on the BSF index, i.e. the p+n+-junction meander length in the poly-Si. Obviously, recombination at the p+n+-junction in the poly-Si limits the implied open circuit voltage Voc,impl. at one sun illumination and the implied pseudo fill factor pFFimpl. to 695 mV and 80%, respectively. After trench isolation, however, Voc,impl (pFFimpl.) values increase up to 730 mV (85.5%), corresponding to a pseudo-efficiency of 26.2% for an assumed short circuit current density Jsc of 42 mA/cm2. We demonstrate a photolithography-free back junction back contacted solar cell with p-type and n-type POLO junctions with an in-house measured champion efficiency of 23.9% on a designated area of 3.97 cm2. This efficiency is mainly limited by the imperfect passivation in the undoped trench regions and at the undoped front side.},

note = {Proceedings of the 6th International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2016)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{MIN2014115,

title = {Limitation of Industrial Phosphorus-diffused Emitters by SRH Recombination},

author = {B Min and H Wagner and A Dastgheib-Shirazi and P P Altermatt},

doi = {10.1016/j.egypro.2014.08.090},

issn = {1876-6102},

year  = {2014},

date = {2014-09-19},

journal = {Energy Procedia},

volume = {55},

pages = {115-120},

note = {Proceedings of the 4th International Conference on Crystalline Silicon Photovoltaics (SiliconPV 2014)},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Min2014b,

title = {Heavily doped Si:P emitters of crystalline Si solar cells: recombination due to phosphorus precipitation},

author = {B Min and H Wagner and A Dastgheib-Shirazi and A Kimmerle and H Kurz and P P Altermatt},

doi = {10.1002/pssr.201409138},

year  = {2014},

date = {2014-08-01},

journal = {physica status solidi (RRL) – Rapid Research Letters},

volume = {8},

number = {8},

pages = {680-684},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Murphy2014b,

title = {Minority carrier lifetime in silicon photovoltaics: The effect of oxygen precipitation},

author = {J D Murphy and R E McGuire and K Bothe and V V Voronkov and R Falster},

doi = {10.1016/j.solmat.2013.06.018},

year  = {2014},

date = {2014-01-01},

journal = {Solar Energy Materials and Solar Cells},

volume = {120},

number = {Part A},

pages = {402-411},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Peaker2012,

title = {Recombination via point defects and their complexes in solar silicon},

author = {A R Peaker and V P Markevich and B Hamilton and G Parada and A Dudas and A Pap and E Don and B Lim and J Schmidt and L Yu and Y Yoon and G Rozgonyi},

doi = {10.1002/pssa.201200216},

year  = {2012},

date = {2012-10-01},

journal = {physica status solidi (a)},

volume = {209},

number = {10},

pages = {1884-1893},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Macdonald2011,

title = {The impact of dopant compensation on the boron–oxygen defect in p- and n-type crystalline silicon},

author = {D Macdonald and A Liu and A Cuevas and B Lim and J Schmidt},

doi = {10.1002/pssa.201000146},

issn = {1862-6319},

year  = {2011},

date = {2011-03-01},

journal = {physica status solidi (a)},

volume = {208},

number = {3},

pages = {559-563},

publisher = {WILEY-VCH Verlag},

keywords = {},

pubstate = {published},

tppubtype = {article}

}