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Single Sided High Throughput Sputter Process Technology for In-Situ Doped n-Type Amorphous Silicon Layers for High Efficiency TOPCon Solar Cells
V. Linss, T. Dietsch, J. Baumann, U. Graupner, J. Hoß, J. Linke, J. Lossen, J.I. Polzin, S. Mack, H. Nagel, M. Bivour, E. Schneiderlöchner
Magnetron Sputtering, High Deposition Rate, Amorphous Silicon, TOPCon
Silicon Materials and Cells
Subtopic: Manufacturing & Production of Si Cells
Event: 8th World Conference on Photovoltaic Energy Conversion
Session: 1DV.4.40
202 - 207
ISBN: 3-936338-86-8
Paper DOI: 10.4229/WCPEC-82022-1DV.4.40
0,00 EUR
Document(s): paper


In this work we report on the development of an industrially relevant in-situ doped sputtering process for depositing 100-150 nm thick aSi(n) layers to passivate the rear contact of TOPCon solar cells. All relevant properties of the poly-Si layers have been optimized using symmetrical lifetime samples. The sputtered aSi(n) layers do not show blistering effects and can be doped with Phosphorus concentrations larger than 1E21 at/cm³ which has been evaluated via calibrated SIMS measurements. ECV measurements of optimized layers after a high temperature anneal at 850-980 °C for 10-30 min confirm the necessary electrically active concentration cP ~ 1-3E20 at/cm³. After tuning the interfacial oxide layer and optimizing the PVD process parameters as well as the annealing process implied open circuit voltages iVoc > 735 mV could be measured on symmetrical lifetime structures at one sun injection density on 1-3 Ωcm n-type Cz-wafers. Corresponding sheet resistances of the 140 nm thick poly-Si layers range from 60-320 Ω/sq and sufficiently low specific contact resistivities below 10 mΩcm² for screen-printed contacts have been determined accompanied by low recombination of J0,met < 65 fA/cm². The best TOPCon solar cell with sputtered poly-Si layers has an efficiency of 23.4 % measured by ISE CalLab PV Cells.