In the rapidly evolving field of photovoltaic technology, crystalline silicon solar cells have maintained their dominance as the leading choice for global solar energy conversion. Among these, the Tunnel Oxide Passivating Contact (TOPCon) architecture has emerged as a particularly promising candidate for industrial adoption. Despite its widespread use, however, the efficiency of TOPCon cells produced at industrial scale has historically lagged behind theoretical limits, restrained by intrinsic electrical performance bottlenecks. This efficiency gap has demanded innovative engineering strategies to push the boundaries of practical solar cell design.
Recently, a groundbreaking advancement out of China has set a new milestone in TOPCon photovoltaic technology, marking a pivotal step toward closing the divide between industrial production capabilities and theoretical efficiency ceilings. Scientists led by Professor YE Jichun at the Ningbo Institute of Materials Technology and Engineering (NIMTE), affiliated with the Chinese Academy of Sciences, have engineered a TOPCon solar cell achieving an unprecedented power conversion efficiency (PCE) of 26.66% at industrial scale. This record-breaking cell represents not only a technical triumph but also a beacon of potential for the solar industry’s future.
The study, appearing in the prestigious journal Nature Energy, details the development of a dual-side electrical refinement strategy tailored for large-area M10 silicon wafers, with an effective surface area of 313.3 cm². This approach addressed key efficiency constraints by simultaneously optimizing the solar cell’s front and rear interfaces, thereby enhancing charge carrier mobility and suppressing recombination losses that typically degrade device performance.
On the front side of the cell, the research team deployed high-sheet-resistance boron emitters, characterized by a resistance of approximately 430 ohms per square. This adjustment enhanced surface passivation—a critical factor that reduces recombination events at the silicon interface—thereby preserving charge carriers generated by solar irradiance. Furthermore, optimized grid layouts were implemented to maximize current collection while minimizing shading losses, cumulatively enhancing the open-circuit voltage and fill factor parameters of the cell.
Conversely, the rear side of the solar cell underwent a significant redesign involving the introduction of an innovative double-layer tunnel oxide and polysilicon structure. This novel configuration was engineered to mitigate metallization-induced degradation, a detrimental effect wherein metal atoms diffuse into the silicon substrate during electrode formation, leading to performance losses. The refined rear structure incorporates a highly crystalline inner polysilicon layer paired with an outer barrier layer, effectively arresting silver diffusion from electrode grids and reinforcing interfacial passivation quality.
The engineering feat did not stop with passive interface improvements. The team strategically thinned the polysilicon layer on the cell’s rear face, which remarkably elevated the cell’s bifaciality to an impressive 88.3%. Bifaciality—a measure of a solar cell’s capacity to harvest light from both front and rear surfaces—plays a crucial role in the overall energy yield, especially under real-world installation conditions where reflected light contributes to power generation. Enhancing bifaciality thus directly translates into higher energy output.
These holistic improvements collectively propelled the cell to an open-circuit voltage (Voc) of 744.6 millivolts and a fill factor (FF) of 85.57%. These metrics indicate extremely efficient charge separation and current collection, vital for achieving top-tier device performance. According to Prof. YE, the realized efficiency corresponds to 83.8% of the theoretical limit of TOPCon solar cells, an achievement that not only sets a new industrial benchmark but also signals significant progress toward closing the efficiency gap.
The research’s success rests on a careful balance of materials science and electrical engineering. The interplay between the high-resistance boron-doped front emitter and the meticulously engineered rear tunnel oxide-sealing polysilicon layers exemplifies a precision approach to managing recombination pathways and charge transport kinetics. By harmonizing these dual interfaces, the team diminished electrical losses that have long hindered large-area TOPCon cells’ performance in industrial settings.
Moreover, the innovation addresses scaling challenges inherent to industrial solar cell fabrication. The choice of M10 wafers, prevalent in commercial manufacturing due to their size and compatibility with existing production lines, underscores the practicability of the new design. The strategy proves that by revisiting and refining fundamental interface structures, existing manufacturing protocols can be elevated to produce efficiencies once deemed out of reach.
The implications of this advancement extend beyond incremental efficiency gains. Achieving a PCE of 26.66% at scale reinforces TOPCon technology’s competitiveness against other high-efficiency solar cell architectures, such as heterojunction and perovskite-based tandem cells. This leap consolidates crystalline silicon’s position as the workhorse of photovoltaic energy, offering pathways to cost-effective, reliable, and high-efficiency solar modules.
This development is especially significant in light of the global push toward renewable energy amid climate urgency. By maximizing energy conversion efficiency while utilizing mature silicon technology, these next-generation TOPCon cells can facilitate broader deployment of solar power with higher returns on investment and reduced land use footprints. The study charts a vibrant course forward for the photovoltaic industry, where fundamental science, inventive engineering, and industrial pragmatism converge to yield next-level solar technologies.
In essence, the work led by Prof. YE and his collaborators represents a milestone moment that catalyzes deeper exploration into interface engineering and cell structure refinement. Their breakthrough approach demonstrates that even within well-established material systems, there remains room for transformative innovation that pushes the boundaries of what is achievable at scale.
As crystalline silicon cells continue to evolve, the dual-side electrical refinement strategy introduced here may serve as a foundational paradigm for future research and development, inspiring further refinements and complementary advances. With efficiency ceilings rising and production technologies evolving, the future of solar power generation looks poised for continued acceleration powered by discoveries such as these.
The research presents a clear, actionable blueprint for industrial manufacturers aspiring to realize top efficiencies without compromising cost or scalability. The convergence of enhanced material interfaces, refined electrical behavior, and practical wafer-scale implementation offers a path forward for the solar industry to meet rising energy demands sustainably and economically.
This milestone achievement heralds a new era for TOPCon solar cells, reaffirming the viability and promise of crystalline silicon technology as a cornerstone in the global quest for clean, affordable, and efficient renewable energy.
Subject of Research: Photovoltaic technology; Crystalline silicon solar cells; Tunnel Oxide Passivating Contact (TOPCon) technology
Article Title: Achieving Record 26.66% Efficiency in Industrial-Scale TOPCon Silicon Solar Cells through Dual-Side Electrical Refinement
News Publication Date: February 24, 2026
Web References:
- Nature Energy article DOI: 10.1038/s41560-026-01982-2
- Ningbo Institute of Materials Technology and Engineering (NIMTE)
References:
- Ye, J. et al. (2026). “Dual-Side Electrical Refinement Strategy for High-Efficiency Industrial TOPCon Solar Cells,” Nature Energy, DOI: 10.1038/s41560-026-01982-2.
Keywords
Crystalline silicon, TOPCon technology, Solar energy, Photovoltaic efficiency, Boron emitter, Tunnel oxide, Polysilicon, Metallization-induced degradation, Bifacial solar cells, Power conversion efficiency, Industrial-scale solar cells, Interface passivation
