TOPCon Solar Efficiency Tiny Boost Has Minimal Impact on Cost Curves

Chinese researchers achieved a 0.07 percentage point efficiency gain in mass-produced TOPCon solar cells through a dual-oxide diffusion barrier, but the improvement is minimal for solar cost curves an

Chinese researchers from Nanchang Hangkong University and ZQi Solar Technology developed a dual-oxide diffusion barrier strategy for industrial TOPCon solar cells. This process—using plasma-enhanced chemical vapor deposition at 435°C—increased average cell efficiency from 27.15% to 27.22% in 966 mass-produced cells (210 × 182.3 mm²). The gain came from reduced contact resistivity (1.54 mΩ cm² to 1.00 mΩ cm²) and suppressed parasitic absorption. Crucially, the study explicitly states this 0.07 percentage point improvement is minimal for solar cost curves and global energy access. The research was published in Solar Energy in 2026 and uses existing PECVD production lines, but the 100-second oxidation duration was optimized for n-type monocrystalline silicon wafers with specific resistivity ranges. The improvement does not meaningfully affect solar affordability or scalability for most energy needs.

Source: pv magazine