Third-generation solar cell technology is undergoing rapid development at Hong Kong Polytechnic University. PolyU researchers have identified breakthrough approaches in perovskite/silicon tandem solar cells, aiming for advances in efficiency, stability and scalability. Their performance analyzes and recommendations aim to increase energy conversion efficiency from approximately 34 percent to 40 percent. The group accelerates commercialization by fostering industry, academia and research collaborations, supporting carbon neutrality plans and the adoption of renewable energy for innovation, including artificial intelligence.
The team, led by Prof. Li Gang and Prof. Yang Guang from PolyU’s Department of Electrical and Electronic Engineering, critically assessed the technical challenges for tandem solar cells. Their paper, published in Nature Photonics, highlights instability issues under environmental stresses such as moisture, oxygen, ultraviolet light and temperature fluctuations. Scaling up from small laboratory equipment to commercial modules requires overcoming obstacles in uniformity, defect management, and large-scale manufacturing.
“Although laboratory-scale devices have shown impressive efficiency improvement, further efforts are needed to improve their reliability, including minimizing efficiency losses from small-area devices to large-area modules,” said Prof. Li Gang. “Special attention should also be paid to ensuring that the manufacturability of materials and methods is in accordance with industry standards.”
Prof. Yang Guang and colleagues call for comprehensive stability testing, aligned with International Electrotechnical Commission standards, to better measure product life and commercial viability. Although initial outdoor testing is underway, reliable long-term results are still limited.
Economic and regulatory issues arise from the use of rare elements and lead in perovskite materials. The team calls for the development of safer alternatives and efficient recycling or containment strategies to make large-scale commercialization both technically and environmentally feasible.
Research report:Towards efficient, scalable and stable perovskite/silicon tandem solar cells
