A research team from the University of Sydney has achieved a groundbreaking milestone in solar technology by creating the largest and most efficient triple-junction perovskite-perovskite-silicon tandem solar cell reported to date. Under the leadership of Professor Anita Ho-Baillie, a prominent figure in nanoscience, the team has demonstrated remarkable advancements in both the efficiency and durability of solar cells. This achievement marks a significant step toward overcoming the technological barriers currently hindering the widespread adoption of perovskite tandem solar cell technology, which holds the potential to revolutionize the solar energy industry.
The impressive feat was accomplished with a 16 cm² triple-junction cell that boasts an independently certified steady-state power conversion efficiency of 23.3 percent. This figure represents the highest efficiency achieved for any large-area cell of its kind, highlighting the substantial progress made by the research team. Meanwhile, at a smaller scale, a 1 cm² cell recorded an astounding efficiency of 27.06 percent, setting new benchmarks for thermal stability. These remarkable efficiency levels underscore the potential of perovskite materials to outperform traditional silicon-based solar technologies when engineered properly.
Published in the esteemed journal Nature Nanotechnology, the team’s findings also contain a historical precedent, as the 1 cm² cell became the first in the world to pass the rigorous Thermal Cycling test conducted by the International Electrotechnical Commission (IEC). This intense test subjects devices to extreme temperature fluctuations ranging from -40 to 85 degrees Celsius over 200 cycles. Remarkably, this prototype retained 95 percent of its efficiency even after over 400 continuous hours of operation under light, highlighting its impressive durability and capability to perform under challenging conditions.
The design and engineering of the triple-junction solar cell feature a complex interplay of three interconnected semiconductors, each tailored to absorb specific parts of the solar spectrum. By capturing a larger portion of solar energy, the design maximizes the conversion efficiency, a crucial factor in the performance of solar panels. The incorporation of advanced materials and innovative engineering strategies has enabled the team to push the limits of efficiency and stability for these advanced solar technologies.
Professor Ho-Baillie, who is also involved with the University of Sydney’s Net Zero Institute, explains that the recent breakthroughs stem from an innovative re-engineering of the chemistry underlying the perovskite material and the overall architecture of the triple junction cell. By replacing methylammonium—often used in high-efficiency perovskite configurations—with rubidium, the research team improved the stability of the perovskite lattice. This substitution minimizes defects and degradation and is a key factor in enhancing overall performance.
Alongside this change, less stable lithium fluoride has been replaced with piperazinium dichloride as a new surface treatment. This alternative treatment has played a pivotal role in improving the longevity and robustness of the solar cells, making them more viable for real-world applications. The team’s approach not only enhances the operational lifespan of the cells but also opens new avenues for optimizing performance through material engineering.
To seamlessly connect the two perovskite junctions, the researchers employed gold at the nanoscale, employing advanced techniques such as transmission electron microscopy to gain insights into how gold nanoparticles interact within the cell structure. Contrary to previous beliefs, the researchers found that gold exists in nanoparticle form rather than as a continuous film, allowing for more efficient coverage and greater control over electric charge flow and light absorption. This pivotal discovery led the team to engineer the distribution of gold nanoparticles to maximize the performance of the solar cells.
One of the most significant challenges facing the solar energy sector is the need for sustainable and economically viable alternatives to traditional energy sources. Perovskite materials, in particular, have drawn attention in recent years due to their relatively low-cost production and their ability to efficiently capture a broader spectrum of sunlight when layered with silicon. Although the potential for these materials has been recognized, the difficulty of scaling them beyond laboratory testing to meet real-world stability requirements has historically limited their adoption.
Professor Ho-Baillie’s statement reflects the significance of their achievement: “This is the largest triple-junction perovskite device yet demonstrated, and it has been rigorously tested and certified by independent laboratories.” She emphasizes that these developments furnish researchers with increased confidence in the scalability of this technology for practical use, which could have far-reaching implications for renewable energy solutions.
International collaboration among researchers from China, Germany, and Slovenia has played an integral role in this groundbreaking work. Their partnership, along with support from the Australian Renewable Energy Agency (ARENA) and the Australian Research Council, has fostered a rich environment for innovation, bringing together diverse knowledge and expertise to tackle complex challenges in solar research.
In addition to pushing boundaries in solar technology, the publication follows a period of recognition for Professor Ho-Baillie’s leadership in solar research. She was honored with the prestigious Eureka Prize for Sustainability Research at the 2025 Australian Museum Eureka Prizes, reflecting her pioneering contributions to perovskite solar technology. The recognition not only underscores her dedication to advancing solar energy solutions but also highlights the vitality of her team’s recent findings.
In light of these advancements, Professor Ho-Baillie adds a note of excitement for the future: “It is an exciting time for solar research. Perovskites are already showing us that we can push efficiencies beyond the limits of silicon alone.” Her remarks echo the broader sentiment within the scientific community regarding the potential to significantly lower energy costs and foster sustainable solutions in line with global climate initiatives. The ongoing progress in perovskite solar technology can enable forthcoming generations to transition to cleaner energy alternatives more rapidly.
In conclusion, the unprecedented advancements achieved by the University of Sydney’s research team represent a monumental step toward a future powered by sustainable solar energy. The exceptional efficiency and durability of their latest perovskite-based solar cells could pave the way for innovative and economically viable options in the quest for renewable energy solutions. As the world grapples with climate change and energy demands, the push toward harnessing triple-junction perovskite technology may well be the catalyst needed to transform solar energy into a cornerstone of global electricity supply.
Subject of Research:
Article Title: Tailoring nanoscale interfaces for perovskite-perovskite-silicon triple-junction solar cells
News Publication Date: 7-Oct-2025
Web References: Nature Nanotechnology
References: Zheng, J. et al. ‘Tailoring nanoscale interfaces for perovskite-perovskite-silicon triple-junction solar cells’
Image Credits: The University of Sydney
