Screen printed copper paste for metallization of IBC solar cells.

Silver (Ag) may limit the growth of the solar industry because of its high cost and limited reserve volume. One solution is to replace Ag with other metals such as copper (Cu). In this study, we use a screen printed Cu paste for the metallization of Interdigitated Back Contact (IBC) solar cells. The Cu paste was applied for replacing most usage of Ag in ZEBRA IBC cells, and only a minor amount of Ag paste was used. The Cu paste was evaluated on printing ability and bulk resistivity and its influence on cell efficiency. Good printing ability and excellent resistivity of 7.5×10−6 Ω·cm were achieved. Simulation and experiment both show that the Cu paste printed cells achieved similar efficiency as Ag paste printed cells. The best Cu cell efficiency is 22.7%, only 0.1%abs lower than the best Ag cell. The Ag usage of the Cu paste printed cell is 4.5 mg/W, which is 70% lower than the current Passivated Emitter and Rear Contact (PERC) cells. The results indicate the screen printed Cu paste is an attractive candidate to metallize IBC cells or to metallize the rear side of other cell concepts. [ABSTRACT FROM AUTHOR]