TOPCon – Technology options for cost efficient industrial manufacturing

Formation of an interfacial tunnel oxide capped by the polysilicon (poly-Si) layer is one of the most promising methods to realize carrier-selective contacts as it offers an evolutionary upgrade to the current mainstream PERC. Currently, PV industry is looking towards different technologically feasible options of transferring this cell concept from laboratory research towards industrial manufacturing. In this paper, we devise cost-driven strategies towards industrial manufacturing of TOPCon-based solar cells after assessing various process routes based on currently production-ready and upcoming future alternative process technologies. Our techno-economic assessment suggests that higher capital and operational costs required for TOPCon concept is distributed unevenly in the process value chain, with a significant fraction in diffusion/annealing and metallization steps. Nevertheless, under given assumptions, TOPCon-concepts are found to remain economically competitive against bifacial PERC in terms of levelized cost of electricity (LCOE), if a minimum absolute gain in cell efficiency Δη > 0.55% for most-conservative and Δη > 0.40% for most-progressive scenarios respectively can be maintained.