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Epitaxy‐free monocrystalline silicon thin films: Identifying the mechanisms behind lifetime degradation upon multiple high‐temperature annealings
Author(s) -
Depauw Valérie,
Simoen Eddy,
Gordon Ivan,
Poortmans Jef
Publication year - 2011
Publication title -
physica status solidi (a)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.532
H-Index - 104
eISSN - 1862-6319
pISSN - 1862-6300
DOI - 10.1002/pssa.201000254
Subject(s) - monocrystalline silicon , wafer , materials science , optoelectronics , annealing (glass) , carrier lifetime , solar cell , epitaxy , deep level transient spectroscopy , silicon , drop (telecommunication) , layer (electronics) , nanotechnology , composite material , electrical engineering , engineering
This work initiates an investigation of the impact of high‐temperature annealings on the material quality of reusable substrates for an “Epifree” solar‐cell process, where the substrate itself provides the active layer of the cell. The minority‐carrier lifetime of simple bulk wafers is monitored by photoconductance decay and the mechanisms affecting it are explored by deep‐level transient spectroscopy. The lifetime is found to drop from the first annealing and then to stabilize to values sufficient for solar‐cell application, at a minimum of 10 µs. The amplitude of this drop is strongly related to the wafer type (MCz or Cz) and no major recombination center could be identified as possible cause.