Chinese researchers have pushed industrial silicon solar cells closer to their theoretical performance limits by achieving a power conversion efficiency (PCE) of 26.66% on a production-ready tunnel oxide passivated contact (TOPCon) design. This result was reported in Nature Energy and represents the highest efficiency recorded so far for industrial-scale TOPCon cells, tells Tech Xplore.
TOPCon architecture has become a leading choice for crystalline silicon photovoltaics because it balances cost and performance while fitting into existing manufacturing infrastructure. Until now, industrial TOPCon efficiencies lagged behind lab-scale records and the fundamental limits predicted for the technology. The new work narrows that gap by combining several material and process innovations on a large M10 wafer with an effective area of roughly 313 cm².
On the cell’s front surface, the team paired high-sheet-resistance boron emitters with optimized metal grids to enhance surface passivation and reduce current losses. On the rear, they developed a novel double-layer tunnel oxide/polysilicon stack that blocks unwanted diffusion of silver from the contacts into the silicon substrate. Strategic thinning of the rear polysilicon layer also boosted the cell’s bifaciality to about 88%, which improves energy yield from light striking the rear surface. These refinements helped deliver an open-circuit voltage of 744.6 mV and a fill factor of 85.57%, key contributors to the overall 26.66% PCE.
Reaching roughly 84% of the theoretical efficiency limit for this class of cells is a significant milestone, especially at an industrial scale where large-area wafers and practical manufacturing constraints often suppress performance. It strengthens TOPCon’s position in the global photovoltaic market and signals that next-generation crystalline silicon cells can continue to squeeze more output from mature materials and processes. Continued improvements could further narrow the gap between production cells and lab records, influencing both utility-scale solar deployment and module cost trajectories in the coming years.