Hydrogen passivation of defects in silicon ribbon grown by the edge-defined film-fed growth process

Abstract

Electrically active defects in edge-defined film-fed grown silicon ribbon solar cells have been passivated using a hydrogen plasma from a Kaufman ion source. Significant improvements in solar cell efficiency for both low diffusion length starting material (∼20 μm) and high diffusion length (∼50 μm) material have been obtained. For the former, passivation has produced solar cell efficiency improvements as high as 41% and in the case of the latter, solar cell efficiencies as high as 14.5% (AM1) have been obtained. Electron beam induced current micrographs are shown which indicate near total defect passivation for at least the top 9 μm of the solar cell.