Interface Study on Laser-structured Plated Contacts for Silicon Solar Cells

Plating of a Ni-Cu stack on laser-structured passivation layer openings is a low-cost metallization approach for silicon solar cells. This work investigates the correlation of microscopic interface properties and contact resistance and mechanical adhesion. Advanced micro characterization methods are applied. Based on the results a model is introduced on how to realize adhesion. The results indicate an important influence of interfacial oxide on the contact resistance and its decrease during post-plating annealing.