Effects of hydrogen plasma annealing on the luminescence from a-Si:H/SiO_2 and nc-Si/SiO_2 multilayers

摘要

Effects of post-hydrogen plasma annealing (HPA) on a-Si:H/SiO_2 and nc-Si/SiO_2 multilayers have been investigated and compared. It is found that photoluminescence (PL) from hydrogen-passivated samples was improved due to the reduction of non-radiative recombination defects. Some interesting difference is that during HPA, atomic hydrogen can directly passivate defects of a-Si:H/SiO_2, which results in the reappearance of luminescence band at 760 nm, while for nc-Si/SiO_2, hydrogen passivation requires additional thermal annealing after nc-Si/SiO_2 multilayer was treated by HPA. It is indicated that higher atomic mobility is needed to passivate defects at nc-Si/SiO_2 interface compared with a-Si:H/SiO_2 interface.