Progress in understanding the current paths and deposition mechanisms of light-induced plating and implications for the process
Advanced metallization techniques for crystalline silicon solar cells have the potential to increase the cell efficiency importantly with only slight alterations of the production process. Compared to the standard process (screen-printing of silver pastes), different two-step processes (seed and plate, as described in ) offer both flexibility and reduced shadowing loss at comparable or improved series resistance. Typically, the seed layer applied in a first step is optimized only to make a contact to the solar cell and does not give sufficient lateral conductivity. This is remedied in the second step (plating), which is in many cases realized by light-induced plating. Most of the investigations dealing with this process so far have been carried out on screen-printed seed layers. However, the most improvement is achieved in combination with new seeding technologies, such as aerosol jetting  or nickel plating , which are used to produce ever narrower seed layers. The plating conditions are very different on such seed layers, e.g. in terms of current density and surface morphology, which both have an important influence on the deposited metal layer. In order to get satisfactory plating results, it is necessary to investigate the deposition onto such substrates.