Current Photovoltaic Research ISSN:2288-3274(Print) 2508-125X(Online)

We have investigated the seed layer formation of front side contact using the inkjet printing process. Conductive silver ink was printed on textured Si wafers with 80 nm thick SiNx anti reflection coating (ARC) layers and thickened by light induced plating (LIP). The inkjet printable sliver inks were specifically formulated for inkjet printing on these substrates. Also, a novel method to prepare nano-sized glass frits by the sol-gel process with particle sizes around 5 nm is presented. Furthermore, dispersion stability of the formulated ink was measured using a Turbiscan. By implementing these glass frits, it was found that a continuous and uniform seed layer with a line width of 40 m could be formed by a inkjet printing process. We also investigated the contact resistance between the front contact and emitter using the transfer length model (TLM). On an emitter with the sheet resistance of 60 Ω/sq, a specific contact resistance (ρc) below 10 mΩ·cm ² could be achieved at a peak firing temperature around 700 °C. In addition, the correlation between the contact resistance and interface microstructures were studied using scanning electron microscopy (SEM). We found that the added glass particles act as a very effective fire through agent, and Ag crystallites are formed along the interface glass layer.