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This content will become publicly available on November 14, 2018

Title: Characterization of high-quality kerfless epitaxial silicon for solar cells: Defect sources and impact on minority-carrier lifetime

We investigate the types and origins of structural defects in thin (<100 μm) kerfless epitaxial single crystal silicon grown on top of reorganized porous silicon layers. Although the structural defect density is low (has average defect density < 10 4 cm -2), localized areas with a defect density > 10 5 cm -2 are observed. Cross-sectional and systematic plan-view defect etching and microscopy reveals that the majority of stacking faults and dislocations originate at the interface between the porous silicon layer and the epitaxial wafer. Localised dislocation clusters are observed in regions of collapsed/deformed porous silicon and at decorated stacking faults. In localized regions of high extended defect density, increased minority-carrier recombination activity is observed. Evidence for impurity segregation to the extended defects (internal gettering), which is known to exacerbate carrier recombination is demonstrated. In conclusion, the impact of the defects on material performance and substrate re-use is also discussed.
Authors:
 [1] ;  [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [3] ;  [3] ;  [1]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Crystal Solar Inc., Santa Clara, CA (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357
Type:
Accepted Manuscript
Journal Name:
Journal of Crystal Growth
Additional Journal Information:
Journal Volume: 483; Journal Issue: C; Journal ID: ISSN 0022-0248
Publisher:
Elsevier
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22); National Science Foundation (NSF); USDOE Office of Defense Programs (DP)
Country of Publication:
United States
Language:
English
Subject:
14 SOLAR ENERGY; Chemical vapor deposition processes; Epitaxial silicon; Impurities; Line defects; Photovoltaics; Semiconducting silicon
OSTI Identifier:
1436471