Mass production of crystalline silicon solar cells with polysilicon-based passivating contacts: An industrial perspective

Silicon solar cells that employ passivating contacts featuring a heavily doped polysilicon layer on a thin silicon oxide (TOPCon) have been demonstrated to facilitate remarkably high cell efficiencies, amongst the highest achieved to date using a single junction on a silicon substrate. Importantly, it has been shown that the polysilicon-based passivating contacts have a high degree of compatibility with existing mass production processes and toolsets, making them an attractive choice for photovoltaic (PV) cell manufacturers to increase the efficiency of their products. With several large PV manufacturers recently announcing plans to push the TOPCon technology into mass production, we review the significant industrial research and development activities that have been undertaken to push the boundaries of the technology and optimise its integration into the existing mass production pipeline. From an industrial perspective, TOPCon fabrication methodology options as well as necessary technological advances in front-side fabrication, cell metallisation and module integration are discussed. The TOPCon technology development is contextualised in terms of larger trends in PV manufacturing, and we look towards the direction of future industrial development.