On the Ink Jetting of Full Front Ag Gridlines for Cost-Effective Metallization of Si Solar Cells

In this letter, we report on the ink-jet full gridline cells with three different Ag dosages (70, 90, and 130 mg) on 75-Ω/sq emitters. We observed that the open-circuit voltage (V_OC), short-circuit current density (J_SC), and fill factor (FF ) were highest for the 130-mg dose and decrease thereafter as the Ag dosage decreases. Because of the decreased FF with decreasing Ag dosage, the efficiency followed the same trend. However, we demonstrated, for the first time, fully ink-jetted front Ag gridlines with an FF of 0.765 and efficiency of 18.4% on 239-cm² commercial CZ wafers with a sheet resistance of 75 Ω/sq . Noteworthy is the achievement of 17.8% efficiency with only 70 mg of Ag, which is ~ 68% less Ag than that used on cells with screen-printed gridlines. This represents a Ag cost saving of ~ $0.245 per 6-inch wafer compared to the screen-printed counterpart with 220 mg of Ag.