Impurity-induced microstructure of grain boundaries in cast silicon. Incidence on electrical properties
Résumé
The role of impurities in polysilicon for photocell has been investigated. Aluminium and carbon residual impurities in the Bridgman and HEM materials were particularly considered. The combination of local electrical, chemical and structural information with high spatial resolution, specifically in transmission electron microscopy, allowed to correlate the crystallography and chemistry with the electrical activity and barriers at grain boundaries. For aluminium it was shown that GB electrical property depends on the localization and environment of this dopant. The different ways for carbon to impair electrical properties are described. The correlation with other impurities and specially oxygen are considered and finally the predominant role of impurities is pointed out.
Mots clés
crystal microstructure
defect electron energy states
elemental semiconductors
silicon
solar cells
transmission electron microscope examination of materials
semiconductor
Bridgman material
impurity induced microstructure
grain boundaries
polysilicon
HEM materials
structural information
high spatial resolution
transmission electron microscopy
crystallography
chemistry
electrical activity
electrical properties
impurities
Si:Al
Si:C
Si:O
Domaines
Articles anciens
Origine : Accord explicite pour ce dépôt
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