1.
S Schäfer; F Haase; C Hollemann; J Hensen; J Krügener; R Brendel; R Peibst
In: Solar Energy Materials and Solar Cells, Bd. 200, S. 110021, 2019, ISSN: 0927-0248.
@article{Schäfer2019c,
title = {26%-efficient and 2 cm narrow interdigitated back contact silicon solar cells with passivated slits on two edges},
author = {S Schäfer and F Haase and C Hollemann and J Hensen and J Krügener and R Brendel and R Peibst},
doi = {10.1016/j.solmat.2019.110021},
issn = {0927-0248},
year = {2019},
date = {2019-09-15},
journal = {Solar Energy Materials and Solar Cells},
volume = {200},
pages = {110021},
abstract = {Perimeter recombination is a relevant loss mechanism, in particular for cells with a large perimeter-to-area ratio and with poorly passivated edges, e.g., cut or cleaved solar cells for shingled modules. We experimentally demonstrate that cut edges can be well passivated during front-end processing. The resulting cells have an efficiency of 26%. The designated cell area of our lab-type highly efficient cells is smaller than the total area of the wafer. This causes recombination losses in the masked perimeter region. We separate the active cell area from the wafer on two sides of the cell by slits to reduce the transport of carriers into the perimeter region. We apply a diffusion model to describe impact of the slits on the perimeter recombination. The slits have an effective surface recombination velocity of down to 9 cm/s, depending on the resistivity of the base. For a base resistivity of 80 Ωcm, the average cell efficiency increases by 0.7 %abs as compared to embedded cells and by 2.3 %abs as compared to laser-cut cells due to the passivated slits.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Perimeter recombination is a relevant loss mechanism, in particular for cells with a large perimeter-to-area ratio and with poorly passivated edges, e.g., cut or cleaved solar cells for shingled modules. We experimentally demonstrate that cut edges can be well passivated during front-end processing. The resulting cells have an efficiency of 26%. The designated cell area of our lab-type highly efficient cells is smaller than the total area of the wafer. This causes recombination losses in the masked perimeter region. We separate the active cell area from the wafer on two sides of the cell by slits to reduce the transport of carriers into the perimeter region. We apply a diffusion model to describe impact of the slits on the perimeter recombination. The slits have an effective surface recombination velocity of down to 9 cm/s, depending on the resistivity of the base. For a base resistivity of 80 Ωcm, the average cell efficiency increases by 0.7 %abs as compared to embedded cells and by 2.3 %abs as compared to laser-cut cells due to the passivated slits.
2.
F Haase; S Schäfer; C Klamt; F Kiefer; J Krügener; R Brendel; R Peibst
In: IEEE Journal of Photovoltaics, Bd. 8, Nr. 1, S. 23-29, 2018, ISSN: 2156-3381.
@article{Haase2018,
title = {Perimeter Recombination in 25%-Efficient IBC Solar Cells With Passivating POLO Contacts for Both Polarities},
author = {F Haase and S Schäfer and C Klamt and F Kiefer and J Krügener and R Brendel and R Peibst},
doi = {10.1109/JPHOTOV.2017.2762592},
issn = {2156-3381},
year = {2018},
date = {2018-01-01},
journal = {IEEE Journal of Photovoltaics},
volume = {8},
number = {1},
pages = {23-29},
abstract = {We introduce a method for the quantification of perimeter recombination in solar cells based on infrared lifetime measurements. We apply this method at a 25.0%-efficient interdigitated back contact (IBC) silicon solar cell with passivating contacts. The implied pseudo-efficiency determined by infrared lifetime mapping is 26.2% at an intermediate process step. The 1.2%abs loss is attributed to a process-related reduction in surface passivation quality, recombination in the perimeter area, and series resistance. The 2 × 2 cm2 -sized cell is processed on a 100 mm wafer. We determine the implied pseudo-efficiency with illuminated and with shaded perimeter area during infrared lifetime mapping. The difference between both implied pseudo-efficiencies yields the efficiency loss by perimeter recombination, which is determined to be 0.4%abs for a wafer resistivity of 1.3 Ω cm and even 0.9%abs for a wafer resistivity of 80 Ω cm.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
We introduce a method for the quantification of perimeter recombination in solar cells based on infrared lifetime measurements. We apply this method at a 25.0%-efficient interdigitated back contact (IBC) silicon solar cell with passivating contacts. The implied pseudo-efficiency determined by infrared lifetime mapping is 26.2% at an intermediate process step. The 1.2%abs loss is attributed to a process-related reduction in surface passivation quality, recombination in the perimeter area, and series resistance. The 2 × 2 cm2 -sized cell is processed on a 100 mm wafer. We determine the implied pseudo-efficiency with illuminated and with shaded perimeter area during infrared lifetime mapping. The difference between both implied pseudo-efficiencies yields the efficiency loss by perimeter recombination, which is determined to be 0.4%abs for a wafer resistivity of 1.3 Ω cm and even 0.9%abs for a wafer resistivity of 80 Ω cm.