High speed non-contact printing for solar cell front side metallization

This work presents a non-contact high speed printing technology for patterning high aspect ratio fine grid lines for the front side metallization of crystallized silicon solar cells. The approach of achieving fine line printing with high aspect ratio was obtained by combining focused work of both material and process together. A modified silver paste was directly patterned by a one-step process onto the silicon wafers without using a screen mask and the line width was as small as 50μm, while the height was around 30μm after firing. The preliminary study of these printed cells showed up to a 0.5% efficiency increase by effectively reducing the shading area while maintaining high grid line conductivity and low contact resistance.