Light-Induced Electrochemical Deposition of Ni for Si Solar Cell Processing

This work outlines the general electrochemical features of the Ni light-induced deposition process. Typical observations for the deposition on textured solar cells are discussed and compared to planar n-Si (100) electrodes. The electrochemical measurements clearly show that after nucleation, Ni-on-Ni deposition is favored over Ni-on-Si, resulting in hemispherical growth. This observation is attributed to a kinetic effect and may be a disadvantage for the growth of ultra-thin contacting layers. In addition, the simultaneous metallization of fingers and busbars shows a significant non-uniformity due to an inevitable variation in current distribution which leads to an enhanced deposition rate for the narrowest features.