Reactions of H with C in Multicrystalline Si Solar-cell Materials

Abstract

AbstractHydrogen is commonly introduced into silicon solar cells to reduce the deleterious effects of defects and to increase cell efficiency. When hydrogen is introduced into multicrystalline Si that is often used for the fabrication of solar cells, the H atoms become trapped by carbon impurities to produce defect structures known at H2*(C). These defects act as both a source and a sink for hydrogen in H-related defect reactions. IR spectroscopy has been used to determine what H- and C-related defects are formed in multicrystalline Si when the carbon concentration is varied. A process that is used by industry to introduce hydrogen into Si solar cells is the post-deposition annealing of a hydrogen-rich SiNx layer. The H2*(C) defects provide a strategy for estimating the concentration and penetration depth of the hydrogen that is introduced by this method.