Innovative silver pastes for the screen printing of the front side metallization of silicon solar cells

A sustainable and renewable electricity generation is one of the big challenges of the 21^st century. Photovoltaics is together with wind energy, hydroelectric power, geothermal energy and biomass the basis of a renewable energy production. The silicon solar cell is the dominating technology in the generation of solar electricity worldwide.

In combination with the coated backside, the linear shaped front side contacts of a silicon solar cell allow for the connection of the cell to a circuit. The silver front side metallization plays a crucial role for cell efficiency.

In the present research study, an innovative formulation concept for the printing paste, which has been invented at our institute, will be further developed. Successive improvement of the printability of the pastes in the screen printing process are supposed to bring our concept closer to the market launch. Line widths of less than 30 μm as well as a high aspect ratio AR > 0.6 combined with a minimum of line interruptions caused by the wires of the printing screen shall contribute to a further improvement in cell efficiency. The paste formulations do not include any non-volatile organic compounds guaranteeing that the sintered conductive paths are free of residual carbon.

The goal of the project is to increase the cell efficiency at a reduced silver consumption per cell, thus further improving the competitiveness of the solar power generation on the energy market.