Since the concept was first introduced by Germany’s Fraunhofer ISE back in 2013, tunnel oxide passivated contact (TOPCon) cells have grown to become one of the biggest prospects for the industry to maintain a steady rise in cell efficiencies. Bringing this technology to scale, however, is not without challenges: Additional processing requirements, plus increased silver consumption, have kept TOPCon cell costs a little above where they need to be for mainstream production. pv magazine examines recent progress and the next steps for TOPCon cell production.