Screen printing is commonly used in the manufacturing of solar panels, particularly in the fabrication of the photovoltaic (PV) cells that convert sunlight into electricity. Here’s how screen printing is typically applied in the solar panel manufacturing process:
Front Contact Grid: Screen printing is used to apply a conductive grid pattern on the front surface of the solar cell. This grid pattern allows for the collection of electricity generated by the cell when sunlight strikes it. The conductive material typically used for this purpose is silver paste, which has good conductivity and adhesion properties.
Back Surface Field: In some solar cell designs, screen printing is also employed to create a back surface field. This involves applying a dopant material, such as phosphorus, to the rear surface of the cell to enhance its light-absorbing properties. The screen-printed dopant material forms a gradient that helps in the efficient collection of charge carriers generated by sunlight.
Metal Paste for Contacting Layers: Screen printing is utilized to deposit metal paste layers that serve as contacts for connecting individual solar cells within a module and for connecting the module to external electrical circuits. Typically, aluminum paste is used for this purpose due to its good conductivity and compatibility with solar cell materials.
Passivation Layers: Screen printing can also be employed to apply passivation layers to the surface of the solar cell. Passivation layers help reduce surface recombination losses, thereby improving the efficiency of the solar cell. These layers are often composed of dielectric materials and are deposited using a screen printing process.
Overall, screen printing plays a crucial role in the manufacturing of solar panels by enabling the precise deposition of various materials and patterns essential for the optimal performance of photovoltaic cells.