Interconnection through vias for improved efficiency and easy module manufacturing of crystalline silicon solar cells

It has become an opportune to develop new module technologies because manufacturers are using larger wafers leading to problems with interconnection of cells. ECN has developed a new cell and module design for crystalline silicon solar cells called pin-up module (PUM) based on old patents (Jong, US Patent 3,903,428, 1975; Pack, US Patent 3,903,427, 1975). In this design a limited number of holes serve as vias for interconnection of the front-side metallisation to a foil at the rear side by using pins. In this way the busbars at the front side are eliminated, thus reducing shadow losses. Calculations show that for 100 cm2 cells, the efficiency will be 0.4% absolute higher. For larger cells, the efficiency gain will be as high as 1%. The PUM concept gives the possibility to increase cell dimensions without reducing the output.