TY - GEN

T1 - Impact of Dielectric Capping Layer Thickness on the Contact Formation between n+-type Passivating Contacts and Screen-printed Fire-through Silver Pastes

AU - Min, Byungsul

AU - Wehmeier, Nadine

AU - Brendemuehl, Till

AU - Haase, Felix

AU - Larionova, Yevgeniya

AU - Nasebandt, Lasse

AU - Schulte-Huxel, Henning

AU - Peibst, Robby

AU - Brendel, Rolf

N1 - Funding Information: The authors thank B. Gehring, M. Pollmann, R. Winter, S. Spaetlich, T. Neubert and D. Sylla for processing solar cells; T. Friedrich for TLM measurements; and K. Bothe, D. Hinken, and M. Wolf (all ISFH) for supporting IV measurements of busbarless solar cells. We also thank M Dhamrin and K. Tsuji from Toyo Aluminium for helpful advices and for providing the aluminium pastes and S. Huebner, T. Dippell, B. Wattenberg, and P. Wohlfahrt from Singulus Technologies AG for constructive discussions. This Work was financially supported by the German Federal Ministry of Economic Affairs and Energy (BMWi) under contact number 03EE1012A (NanoPERC) and a part of this work was supported under contact number 0324171C (Nextstep).

PY - 2022/8/24

Y1 - 2022/8/24

N2 - This paper presents the approach to reduce the deterioration of poly-Si based passivating contacts through screen-printed silver pastes by modifying the SiNx capping layer thickness and firing temperature. Its impact is investigated by fabricating p-type back junction solar cells featuring the passivating contacts at the cell rear side. We demonstrate that the improved contact formation without compromising of the quality of passivating contacts is possible if the firing temperature is optimized for the chosen SiNx layer thickness. On the full area of M2-sized industrial p-type Cz wafers, we achieve an open-circuit voltage of 716 mV and an efficiency of 22.6%, both independently. A median contact resistivity of 2 mΩcm2 is measured with transfer length method for the optimized SiNx layer thickness and firing temperature. The investigation with scanning electron microcopy shows that certain amount of small etch pits are necessary to form the contact between screen-printed silver and phosphorus-doped poly-Si properly. The best efficiency that we achieved so far with this cell concept is 22.9 %, independently confirmed.

AB - This paper presents the approach to reduce the deterioration of poly-Si based passivating contacts through screen-printed silver pastes by modifying the SiNx capping layer thickness and firing temperature. Its impact is investigated by fabricating p-type back junction solar cells featuring the passivating contacts at the cell rear side. We demonstrate that the improved contact formation without compromising of the quality of passivating contacts is possible if the firing temperature is optimized for the chosen SiNx layer thickness. On the full area of M2-sized industrial p-type Cz wafers, we achieve an open-circuit voltage of 716 mV and an efficiency of 22.6%, both independently. A median contact resistivity of 2 mΩcm2 is measured with transfer length method for the optimized SiNx layer thickness and firing temperature. The investigation with scanning electron microcopy shows that certain amount of small etch pits are necessary to form the contact between screen-printed silver and phosphorus-doped poly-Si properly. The best efficiency that we achieved so far with this cell concept is 22.9 %, independently confirmed.

UR - http://www.scopus.com/inward/record.url?scp=85137449225&partnerID=8YFLogxK

U2 - 10.1063/5.0089239

DO - 10.1063/5.0089239

M3 - Conference contribution

AN - SCOPUS:85137449225

T3 - AIP Conference Proceedings

BT - SiliconPV 2021 - 11th International Conference on Crystalline Silicon Photovoltaics

A2 - Brendel, Rolf

A2 - Ballif, Christophe

A2 - Dubois, Sebastien

A2 - Glunz, Stefan

A2 - Hahn, Giso

A2 - Poortmans, Jef

A2 - Verlinden, Pierre

A2 - Weeber, Arthur

T2 - 11th International Conference on Crystalline Silicon Photovoltaics, SiliconPV 2021

Y2 - 19 April 2021 through 23 April 2021

ER -