Abstract
Ni/Cu/Ag contact formed by plating has continuously been studied as a future metallization technique of solar cells due to the lower cost of material and better electrical performance compared with the screen-printed Ag contact. For the metallization of samples, native oxide on a laser-patterned Si area was etched with a buffered oxide etch solution for uniform plating. A Ni seed layer for Cu plating was deposited by using alkaline electroless plating. Afterward, a Cu-Ag metal stack was plated by light-induced plating followed by annealing in a tube furnace with an N 2 gas atmosphere. This annealing process forms NiSi x , which enhances contact resistance and adhesion. However, Ni penetration through the emitter layer can produce shunting paths, which decrease cell performance. In this experiment, 2.6 N/mm was obtained as the highest adhesion result. In addition, voids that can degrade adhesion were observed at the interface of Cu-Ag due to the Kirkendall effect. According to the experiment's results, the suggestion of annealing condition was discussed to have good electrical and physical properties of plated Ni/Cu/Ag front contact.