As global demand for cleaner and more efficient energy sources intensifies, solar power remains one of the most promising solutions. Yet, even as photovoltaic technology advances, engineers continue to chase a balance between efficiency, stability, and cost.
Among the emerging contenders, perovskite/silicon tandem solar cells (TSCs) have garnered attention for their potential to outperform traditional silicon cells; however, scaling them up for commercial use remains a challenge.
Now, an engineering team at The Hong Kong Polytechnic University (PolyU) has reported significant progress in tackling these barriers.
Led by Prof. Li Gang and Prof. Yang Guang from the Department of Electrical and Electronic Engineering, the researchers are working to raise the energy conversion efficiency of perovskite/silicon TSCs from around 34% to nearly 40%.
Their findings provide a blueprint for improving efficiency, stability, and scalability, key steps toward mass deployment and alignment with China’s carbon neutrality goals.
The PolyU team conducted a detailed review of TSC performance, analysing how to translate lab success into real-world durability.
“While lab-scale devices have shown impressive efficiency advancement, further efforts are needed to improve their reliability, including minimising efficiency losses from small-area devices to large-area modules,” said Prof. Li Gang.
The team highlighted that perovskite materials remain vulnerable to moisture, oxygen, ultraviolet light, and temperature fluctuations, all of which degrade performance over time.
Scaling these devices into full modules also introduces manufacturing challenges, such as ensuring material uniformity and controlling defects. Although outdoor tests have begun, long-term reliability data remain limited.
To address these gaps, the researchers recommend accelerated stability testing based on International Electrotechnical Commission standards. “Special focus should also be given to ensuring that the manufacturability of materials and methods aligns with industrial standards,” Prof. Li added.
Addressing environmental and material concerns
While perovskite materials are relatively affordable, their use of rare elements and lead raises environmental concerns.
The PolyU team urges the development of sustainable alternatives and effective lead management or recycling systems to ensure the technology’s long-term viability.
Their approach combines scientific innovation with environmental responsibility, positioning perovskite/silicon TSCs as a cornerstone for future clean energy systems, provided the industry can meet both performance and sustainability benchmarks.
Driving collaboration for commercial rollout
The researchers also emphasise the need for collaboration across academia, industry, and research institutions.
“The development of efficient and reliable perovskite/silicon TSCs must address these remaining scientific challenges to achieve lower levelised electricity costs,” said Prof. Yang Guang.
He added that integrating material science, device engineering, and economic modelling will be crucial for commercial readiness.
The team envisions this work accelerating the transition from laboratory prototypes to large-scale production, aligning closely with the nation’s carbon peaking and neutrality targets.
“By providing a stable supply of high-efficiency renewable energy, we aim to deliver green and reliable power support for high-energy-consuming industries such as artificial intelligence, thereby helping to achieve a low-carbon transformation of the energy structure,” Prof. Yang said.
If successful, PolyU’s 40% efficiency goal could push perovskite/silicon tandem solar cells from research labs to rooftops and industrial grids, marking a decisive step toward a cleaner energy future.
The study is published in the journal Nature Photonics.