Realistic Estimation of Industrial TOPCon Cell Efficiency

Over the past year, there has been a sharp increase in the installed manufacturing capacity and efficiency of n-type Tunnel-Oxide Passivated Contact (TOPCon) solar cells with reported efficiency and open-circuit voltage (Voc) values of above 26.0% and 730 mV, respectively. Modules based on commercial TOPCon cells with Cell to Module (CTM) values of close to 100% are expected to deliver higher wattage than the achieved wattage in production. In this work, commercial 16 Busbar (BB) M10 TOPCon solar cells of labelled efficiency of 25.65% and 25.11% are characterized via Quantum Efficiency (QE) and I-V measurements under STC and Quokka3 based simulations of industrial TOPCon cells have been carried out to correlate with the QE and I-V measurements. The study reveals that the real efficiency of commercial M10 TOPCon is higher by 1.0% absolute compared with the labelled efficiencies. The main difference is attributed to the higher short-circuit current density (Jsc). The simulations also show that the commercial TOPCon cells should have efficiency in the range of 24.0% to 24.8% based on the variation of the base resistivity and minority carrier lifetime.