TY - JOUR

T1 - 26%-efficient and 2 cm narrow interdigitated back contact silicon solar cells with passivated slits on two edges

AU - Schäfer, S.

AU - Haase, Felix

AU - Hollemann, Christina

AU - Hensen, J.

AU - Krügener, Jan

AU - Brendel, Rolf

AU - Peibst, Robby

N1 - Funding information: The authors thank the Federal Ministry of Economic Affairs and Energy (BMWi) (grant number 0325827A , project 26+) and the State of Lower Saxony for funding this work, Hilke Fischer, Annika Raugewitz, Sabine Schmidt (all from ISFH), Raymond Zieseniss and Guido Glowatzki (both from Institute of Electronic Materials and Devices) for sample processing and Tobias Neubert and David Sylla (both ISFH) for fruitful discussions about the laser process.

PY - 2019/9/15

Y1 - 2019/9/15

N2 - 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.

AB - 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.

KW - Back-contact solar cell

KW - Edge loss

KW - Passivating contacts

KW - Perimeter recombination

UR - http://www.scopus.com/inward/record.url?scp=85068079099&partnerID=8YFLogxK

U2 - 10.1016/j.solmat.2019.110021

DO - 10.1016/j.solmat.2019.110021

M3 - Article

AN - SCOPUS:85068079099

VL - 200

JO - Solar Energy Materials and Solar Cells

JF - Solar Energy Materials and Solar Cells

SN - 0927-0248

M1 - 110021

ER -