Screen-printed high performance aluminum and polymer pastes for n-type solar cells

This paper presents high performance Al pastes for n-type solar cells with p-type backside. These pastes were screen printed and subsequently fired in a belt furnace to form rear-Al emitters. Internal Quantum Efficiency (IQE), and full I-V curve characterization and curve fitting to investigate leakage currents were carried out to study the effect of glass frits, additives and firing profiles. The paste performance including bow and adhesion are also presented. This paper also presents a screen printable, low temperature curable conductive polymer paste and its application in n-type solar cell fabrication. The solderable polymer paste enables full Al coverage of the back surface. Its excellent adhesion and low contact resistivity to Al allow it to be used as rear Ag busbar.