TY - JOUR

T1 - Wet-Chemically Grown Interfacial Oxide for Passivating Contacts Fabricated With an Industrial Inline Processing System

AU - Min, Byungsul

AU - Noack, Philipp

AU - Wattenberg, Bianca

AU - Dippell, Torsten

AU - Schulte-Huxel, Henning

AU - Peibst, Robby

AU - Brendel, Rolf

N1 - Funding Information: This work was supported by the State of Lower Saxony and the German Federal Ministry for Economic Affairs and Climate Action (BMWK) underGrant 03EE1012A (NanoPERC).

PY - 2024/3

Y1 - 2024/3

N2 - This article presents for the first time the application of wet-chemical interfacial oxide from an industrial inline processing system for poly-Si-based passivating contacts. An excellent passivation quality is achieved by creating an interfacial oxide with a very short exposure time of 90 s in ozonized water and by adjusting the annealing temperature in a tube furnace, resulting in surface recombination current densities of 4 fA/cm 2 and 1.2 fA/cm 2 before and after a hydrogenation step, respectively. Detailed electrical characterization reveals the interplay of in-diffusion of P into the wafer and hydrogenation step. Our investigation shows that the optimum annealing temperature can differ before and after the hydrogenation step. The developed wet-chemical interfacial oxide is successfully implemented in back junction solar cells on large-area gallium-doped p-type silicon wafers (156.75 × 156.75 mm 2) featuring a phosphorus-doped poly-Si-based passivating contact at the rear side. The best cell has an efficiency of 23.6% and an open-circuit voltage of 719 mV, independently confirmed by ISFH CalTeC in Germany. Our cost calculation shows a saving of up to 17.2% in capital expenditure, 5.2% p.a. in operating expense, and 9.0% in the footprint if the interfacial oxide is formed by an inline wet-chemical processing system instead of a plasma chamber.

AB - This article presents for the first time the application of wet-chemical interfacial oxide from an industrial inline processing system for poly-Si-based passivating contacts. An excellent passivation quality is achieved by creating an interfacial oxide with a very short exposure time of 90 s in ozonized water and by adjusting the annealing temperature in a tube furnace, resulting in surface recombination current densities of 4 fA/cm 2 and 1.2 fA/cm 2 before and after a hydrogenation step, respectively. Detailed electrical characterization reveals the interplay of in-diffusion of P into the wafer and hydrogenation step. Our investigation shows that the optimum annealing temperature can differ before and after the hydrogenation step. The developed wet-chemical interfacial oxide is successfully implemented in back junction solar cells on large-area gallium-doped p-type silicon wafers (156.75 × 156.75 mm 2) featuring a phosphorus-doped poly-Si-based passivating contact at the rear side. The best cell has an efficiency of 23.6% and an open-circuit voltage of 719 mV, independently confirmed by ISFH CalTeC in Germany. Our cost calculation shows a saving of up to 17.2% in capital expenditure, 5.2% p.a. in operating expense, and 9.0% in the footprint if the interfacial oxide is formed by an inline wet-chemical processing system instead of a plasma chamber.

KW - Annealing

KW - Furnaces

KW - Interfacial oxide

KW - passivating contact

KW - Passivation

KW - Photovoltaic cells

KW - Production

KW - Silicon

KW - Temperature measurement

KW - wet-chemical

UR - http://www.scopus.com/inward/record.url?scp=85183979498&partnerID=8YFLogxK

U2 - 10.1109/JPHOTOV.2024.3352836

DO - 10.1109/JPHOTOV.2024.3352836

M3 - Article

AN - SCOPUS:85183979498

VL - 14

SP - 233

EP - 239

JO - IEEE Journal of Photovoltaics

JF - IEEE Journal of Photovoltaics

SN - 2156-3381

IS - 2

ER -