UNSW team studies aluminum contacts in TOPCon cells to cut silver use

A research team led by the University of New South Wales, with Osaka University, Toyo Aluminum K.K., and Trina Solar, explored aluminum as a low-cost alternative to silver in TOPCon solar cells. Trina Solar, based in Changzhou, China, produces high-efficiency solar modules for global deployment. The study introduced tailored aluminum pastes that reduced alloying with polycrystalline silicon, resulting in lower contact recombination levels. Researchers tested aluminum contact behavior under various firing conditions to identify settings that ensured strong passivation and low resistivity. The aluminum-contact TOPCon cell achieved 22.9% efficiency, 0.8% lower than the silver-contact reference at 23.7%. Simulation results indicated that further design refinements could close the remaining performance gap. Published on ScienceDirect, the findings support scalable photovoltaic manufacturing with reduced silver dependence through aluminum-based rear contact integration.