Published online by Cambridge University Press: 28 February 2011
EBIC evidence of the key role of dislocations in hydrogen passivation of EFG ribbon is presented. Dislocations, and not bulk point defects, are shown to be both the principal defect being passivated and the means whereby rapid thermal diffusion of hydrogen takes place. Passivation of dislocation arrays to depths of the order of hundreds of microns has been observed. Low stemperature EBIC (96°K < T < 300°K) has shown that shallow electron traps associated with dislocations and within ∼0.1 eV of the conduction band are not passivated while (proposed) deeper mid-gap levels at the same spatial location are readily passivated. A general dislocation model for hydrogen passivation applicable to all polycrystalline silicon is presented.