Taking monocrystalline silicon to the ultimate lifetime limit

Abstract: A central quantity to assess the high quality of monocrystalline silicon (on scales beyond mere purity) is the minority charge carrier lifetime. We demonstrate that the lifetime in high purity float zone material can be improved beyond existing observations, thanks to a deeper understanding of grown-in defects and how they can be permanently annihilated. In a first step we investigate the influence of several process sequences on the lifetime by applying a low temperature superacid passivation treatment. We find that a pre-treatment consisting of an oxidation at 1050°C followed by a POCl3 diffusion at 900°C can improve the lifetime by deactivating or eliminating grown-in defects. Then, pre-treated wafers of different float zone materials are passivated with three state-of-the-art layer stacks. Very high effective lifetime values are measured, thereby demonstrating the high quality of the surface passivation schemes and the pre-treated silicon wafers. The measured effective lifetimes exceed previous records, and we report an effective lifetime of 225ms measured on a 200µm thick 100Ωcm ntype silicon wafer symmetrically passivated with a layer stack of a thin thermally grown oxide and a polycrystalline layer (the TOPCon layer stack)

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Solar energy materials & solar cells. - 185 (2018) , 252-259, ISSN: 1879-3398

Classification and Topics

• Keyword: Solarzelle ; Silicone ; Topcon ; Supersäuren ; Rekord

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2020
• Creator: Niewelt, Tim ; Richter, Armin ; Kho, Teng Choon ; Grant, Nicholas Ewen ; Bonilla, Ruy Sebastian ; Steinhauser, Bernd ; Polzin, Jana Isabelle ; Feldmann, Frank ; Hermle, Martin ; Murphy, John D. ; Phang, Sieu Pheng ; Kwapil, Wolfram ; Schubert, Martin

Further information

• DOI: 10.1016/j.solmat.2018.05.040
• URN: urn:nbn:de:bsz:25-freidok-1659952
• Rights: Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 14.08.2025, 10:58 AM CEST