Title:	Single Sided High Throughput Sputter Process Technology for In-Situ Doped n-Type Amorphous Silicon Layers for High Efficiency TOPCon Solar Cells
Author(s):	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
Keywords:	Magnetron Sputtering, High Deposition Rate, Amorphous Silicon, TOPCon
Topic:	Silicon Materials and Cells
Subtopic:	Manufacturing & Production of Si Cells
Event:	8th World Conference on Photovoltaic Energy Conversion
Session:	1DV.4.40
Pages:	202 - 207
ISBN:	3-936338-86-8
Paper DOI:	10.4229/WCPEC-82022-1DV.4.40
Price:	0,00 EUR
Document(s):	paper

Abstract/Summary:

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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.