LONGi sets record of 25.09% for N-Type TOPCon cell efficiency By LONGi Email Testing at the Institute for Solar Energy Research (ISFH) in Hamelin, Germany, has confirmed that the conversion efficiency of N-type monocrystalline bifacial TOPCon cells developed at LONGi’s Cell R&D Center has reached 25.09%, the first time that the efficiency of a TOPCon cell based on a commercial size silicon wafer has exceeded 25%. Based on its original innovative industrialized cell technology, the LONGi Cell R&D Center continually provides upgrades to PV industry technology. Indeed, in January 2019 the company achieved 24.06% front conversion efficiency for a monocrystalline bifacial PERC solar cell, a record which still stands.