A Brief Review of TOPCon Solar Cell and its Future Perspectives

The utilization of poly-Si/SiOx structures for passivating contacts, commonly referred to as TOPCon (Tunnel Oxide Passivated Contacts), presents a significant opportunity to enhance the efficiency of crystalline silicon solar cells. Laboratory-scale implementations have achieved efficiencies exceeding 26%, while industrial-scale cells have demonstrated efficiencies surpassing 24%. The reported efficiency pertains to a larger wafer that includes metal fingers and bus-bars under full illumination and simulated conditions. This work shows that the device’s actual deployment is severely hampered by recombination losses in the emitter, which span surface, bulk and metal contacts. The historical evolution of such contact structures, which started decades ago, is summarized in this paper together with the state-of-the-art in both laboratory and industry settings to date.