ELECTRICAL ACTIVITY OF GRAIN BOUNDARIES IN SILICON GROWN WITH AN ALUMINIUM CONTENT GRADIENT T. BENABBAS, C. CABANEL, J.Y. LAVAL, J.L. PASTOL and NGUYEN DINH HUYNH J. Phys. Colloques, 51 C1 (1990) C1-439-C1-444 DOI: 10.1051/jphyscol:1990168