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Title: Hydrogen passivation of poly-Si/SiO x contacts for Si solar cells using Al 2O 3 studied with deuterium

Here, the interplay between hydrogenation and passivation of poly-Si/SiO x contacts to n-type Si wafers is studied using atomic layer deposited Al 2O 3 and anneals in forming gas and nitrogen. The poly-Si/SiO x stacks are prepared by thermal oxidation followed by thermal crystallization of a-Si:H films deposited by plasma-enhanced chemical vapor deposition. Implied open-circuit voltages as high as 710 mV are achieved for p-type poly-Si/SiO x contacts to n-type Si after hydrogenation. Correlating minority carrier lifetime data and secondary ion mass spectrometry profiles reveals that the main benefit of Al 2O 3 is derived from its role as a hydrogen source for chemically passivating defects at SiO x; Al 2O 3 layers are found to hydrogenate poly-Si/SiO x much better than a forming gas anneal. By labelling Al 2O 3 and the subsequent anneal with different hydrogen isotopes, it is found that Al 2O 3 exchanges most of its hydrogen with the ambient upon annealing at 400 °C for 1 h even though there is no significant net change in its total hydrogen content.
ORCiD logo [1] ; ORCiD logo [2] ;  [1] ; ORCiD logo [2] ;  [1] ; ORCiD logo [2] ; ORCiD logo [1]
  1. National Renewable Energy Lab. (NREL), Golden, CO (United States)
  2. Eindhoven Univ. of Technology, Eindhoven (The Netherlands)
Publication Date:
Report Number(s):
Journal ID: ISSN 0003-6951
Grant/Contract Number:
AC36-08GO28308; SETP EE00030301
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 112; Journal Issue: 20; Journal ID: ISSN 0003-6951
American Institute of Physics (AIP)
Research Org:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
Sponsoring Org:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar Energy Technologies Office (EE-4S)
Country of Publication:
United States
36 MATERIALS SCIENCE; 71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; electrical properties; passivation; atomic layer deposition; secondary ion mass spectroscopy; isotopes; chemical reactions
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1437089