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Investigation of uniformity in fused quartz crucibles for Czochralski silicon ingots

Abstract

As there is an increased demand for monocrystalline silicon based solar cells, there is an increased interest in stronger and more durable fused quartz crucibles used in the Czochralski process. In this study we focused on the uniformity of hydroxyl impurities in these crucibles, and its potential influence on viscosity of the crucible by combining data from IR-microscopy and a self-made viscosity measurement setup. A half of a fused quartz crucible manufactured from two types of sands was studied, the OH groups content was mapped, and the viscosity at 1500 °C was measured. Local variations in the OH groups content of on average 26.7 ppm difference between the top and the bottom of the crucible were detected. The viscosity measurements further confirmed the crucible’s inhomogeneity as no clear trends or direct correlations to the OH groups content were observed. The correlation between the different sand types used for crucible manufacturing and the OH groups content was also investigated in four samples originating from four different crucibles. Two different trends in the OH groups distribution were found: while two of the studied crucibles showed an increased OH groups content in the boundary between the bubble free and the bubble containing layer, the other two showed an increased and maximum OH groups content in the bubble containing layer, and the link between the sand types and the OH groups content was confirmed. The source of the local inhomogeneities and the two different trends of OH groups distribution can possibly be attributed to the sand quality, the sand particle size, and the difference in the manufacturing process, such as thermal history or distribution of sand.
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Category

Academic article

Language

English

Author(s)

  • Gabriela Kazimiera Warden
  • Petra Ebbinghaus
  • Martin Rabe
  • Mari Juel
  • Bartlomiej Gawel
  • Andreas Erbe
  • Marisa Di Sabatino

Affiliation

  • SINTEF Industry / Sustainable Energy Technology
  • Max Planck Society
  • Norwegian University of Science and Technology
  • Diverse norske bedrifter og organisasjoner

Year

2024

Published in

Journal of Crystal Growth

ISSN

0022-0248

Volume

645

View this publication at Norwegian Research Information Repository