Impact of the Silicon Substrates and Activation in the Nickel Electroless Plating

Our purpose is to deposit a very well-controlled thickness of electroless nickel to form contact lines for silicon solar cells. For that, an accurate understanding of the nickel electroless mechanism is necessary. The main step is to control the beginning of nickel nucleation at very short times. In this study, a commercial bath was employed. First, we have demonstrated that a too oxidized silicon surface block the nickel deposition. Then, the first steps of nucleation were finely studied using both SEM-FEG and XPS analyses. And to finish, a nickel electroless deposition mechanism was proposed.