News

Prof. YANG Guang and Prof. LI Gang publish review article on perovskite/silicon tandem solar cells

A review article titled “Towards efficient, scalable and stable perovskite/silicon tandem solar cells” co-authored by Prof. YANG Guang, Assistant Professor in the Department of Electrical and Electronic Engineering, and Prof. LI Gang, Chair Professor in the same department, was recently published in Nature Photonics. Perovskite/silicon tandem solar cells (TSCs) have emerged as a highly promising technology for photovoltaic energy harvesting, already surpassing the efficiency limits of traditional single-junction solar cells. Although recent power conversion efficiencies have approached 35%, perovskite/silicon TSCs still face a significant gap compared to their theoretical maximum. Additionally, challenges related to long-term operational stability and large-scale manufacturing must be overcome before this technology can be widely commercialised. This review provides a comprehensive overview of the latest advancements in perovskite/silicon TSCs, with a particular focus on three critical aspects: efficiency, stability, and scalability. The authors also offer a critical assessment of the remaining challenges and discuss the prospects for the future development of this technology. Prof. Yang is currently a Member of the Photonics Research Institute (PRI), Otto Poon Charitable Foundation Research Institute for Smart Energy (RISE) and Research Institute for Advanced Manufacturing (RIAM). Prof. Li serves as the Associate Director of RISE, Management Committee Member of PRI, and Member of Research Institute for Intelligence Wearable Systems (RI-IWEAR) and Research Institute for Sustainable Urban Development (RISUD). Read the full paper: https://www.nature.com/articles/s41566-025-01732-y Press release: English - https://polyu.me/4p2AIjN; Chinese - https://polyu.me/486CHOc Online coverage: Tech Xplore - https://polyu.me/47K8ByM The National Tribune - https://polyu.me/3JSDjhe Mirage - https://polyu.me/4p1YtIv City Times - https://polyu.me/4pnGT2b

Prof. CAI Jing pioneer safer, AI-powered MRI imaging for nasopharyngeal carcinoma

PolyU researchers have made a breakthrough in MRI imaging for nasopharyngeal carcinoma (NPC). Traditionally, MRI scans for NPC rely on gadolinium-based contrast agents (GBCAs) to enhance tumour visibility. However, GBCAs pose health risks, including nephrogenic systemic fibrosis and potential accumulation of gadolinium in human brain. Led by Prof. CAI Jing, Management Committee Member of Research Institute for Intelligent Wearable Systems (RI-IWEAR), Research Institute for Smart Ageing (RISA), Professor and Head of Department of Health Technology and Informatics, and his team have developed an AI-powered, contrast-free MRI imaging, offering a safer diagnostic alternative. Their innovative Multimodality-Guided Synergistic Neural Network (MMgSN-Net) synthesises virtual contrast-enhanced images using information from T1- and T2-weighted scans, eliminating the use of GBCAs. Building on this, the team has introduced the Pixelwise Gradient Model with Generative Adversarial Network for Virtual Contrast Enhancement (PGMGVCE), which further improves image texture and detail. Comparative studies show that PGMGVCE matches MMgSN-Net in accuracy and excels in texture representation, which is crucial for precisely delineating the boundaries of NPC tumours. The findings highlight the importance of integrating multiple imaging modalities and advanced AI techniques to enhance diagnostic quality. These advancements promise safer MRI procedures for NPC patients, particularly those experiencing side-effects from contrast agents, and pave the way for improved cancer diagnosis and treatment planning. Future research will focus on expanding datasets and incorporating more MRI modalities to further boost diagnostic capabilities. Online coverage: Eurek Alert - https://polyu.me/45hPQ5R Bioengineer - https://polyu.me/413mNAp Technology Network - https://polyu.me/4mH2bWU Mirage News - https://polyu.me/3UsjhvF

Prof. WENG Qihao publishes comment article on urban visual-spatial intelligence

Prof. WENG Qihao, Associate Director of the Research Institute for Land and Space (RILS), Chair Professor of Geomatics and Artificial Intelligence and Global STEM Scholar in the Department of Land Surveying and Geo-Informatics, together with his research team has recently published an article titled “Urban visual-spatial intelligence: linking human and sensor perception for sustainable urban development” in npj Urban Sustainability.  The article points out that UVSI integrates human perception with advanced sensor technologies, moving beyond traditional smart city models that prioritise technology alone. By combining data from sources such as satellite imagery, IoT sensors, mobile devices, and social media, UVSI provides a real-time, multi-dimensional understanding of urban environments. A central feature of UVSI is its collaborative framework, ensuring continuous feedback between residents, technology, and urban spaces. This adaptive approach supports dynamic urban management and aligns with the United Nations Sustainable Development Goals, particularly SDG 11 for sustainable cities. UVSI informs policy-making, infrastructure planning, disaster monitoring, and climate action, while upholding privacy and public trust. Nonetheless, challenges persist, especially the integration of diverse types of data across geographical contexts and addressing associated biases. The research team believes that future research will focus on open-source models, digital twins, and ethical, AI-driven urban planning. As cities expand, UVSI’s holistic method promises more resilient, inclusive, and liveable urban environments by bridging technology and human experience, ensuring urban development remains responsive to the needs of all communities. Read the full paper: https://www.nature.com/articles/s42949-025-00256-2

PolyU research achieves record efficiency in semi-transparent solar cells, advancing the development of building-integrated photovoltaics

Prof. LI Gang, Chair Professor of Energy Conversion Technology and Sir Sze-yuen Chung Endowed Professor in Renewable Energy of the PolyU Department of Electrical and Electronic Engineering, together with Research Fellow Dr YU Jiangsheng, have recently developed an innovative parameter to evaluate the potential of photoactive materials for ST-OPVs. By screening for the most promising materials and their combinations, the research has advanced the development of high-performance ST-OPVs and paved the way for their widespread applications in smart windows and sustainable buildings. With their unique discrete absorption, low-cost production and environmental sustainability, ST-OPVs have very significant development potential in the field of building-integrated photovoltaics (BIPV). To fully realise their potential in the BIPV market and beyond, scientists have combined different materials and leveraged advanced device engineering technologies to enhance the efficiency and stability of ST-OPVs, while ensuring that the colour of the product appears natural under sunlight so that the photovoltaic system does not compromise the building’s visual appeal. They introduced a dimensionless parameter, FoMLUE, to screen a series of classic photoactive materials. It takes into account the materials’ average visual transmittance, bandgap and current density by investigating their normalised absorbance. The researchers found that ST-OPVs based on the ternary materials with the highest FoMLUE values demonstrated enhanced thermal insulation and operational stability compared with their counterparts, and achieved record light utilisation efficiency of 6.05% - the highest figure of merit reported for any semi-transparent solar cell. Their research additionally revealed the influence of geographical factors on ST-OPV performance. To explore the power generation and energy-saving performance of ST-OPV glazed windows, the research team developed a transient model to simulate power output and assess its impact on building space cooling and heating loads. The model, applied in 371 cities across China, has shown that over 90% achieved annual load reductions. Geographical analysis has further indicated that regions with hot summers and warm winters are the most suitable for the installation of ST-OPV glazed windows, with the annual total energy saving in these regions reaching up to 1.43 GJ m ⁻². A paper reporting the research, “Semitransparent organic photovoltaics with wide geographical adaptability as sustainable smart windows,” has been published in Nature Communications. Moving forward, the research team will continue to enhance the long-term stability of ST-OPVs and scale up development to large-area solar modules, both of which are essential for achieving commercialisation. Prof. Li is currently the Associate Director of Otto Poon Charitable Foundation Research Institute for Smart Energy (RISE), Management Committee Member of Photonics Research Institute (PRI), and Member of Research Institute for Intelligence Wearable Systems (RI-IWEAR) and Research Institute for Sustainable Urban Development (RISUD).   Press release: https://polyu.me/3LnaOZi Full paper: https://www.nature.com/articles/s41467-025-62546-8 Online coverage: Tech Xplore - https://polyu.me/3IXUcH1 Mirage - https://polyu.me/3WiQSsY Ta Kung Pao - https://polyu.me/3L46BJY (Chinese only) Bastille Post - https://polyu.me/3WNvlZA (Chinese only) Eurek Alert - https://polyu.me/4oy1Tm9 Bauhinia - https://polyu.me/47Cz16B (Chinese only) Unwire.hk - https://polyu.me/3WksS8Y (Chinese only) Science Net - https://polyu.me/4o6YyLa (Chinese only)

Prof. John SHI on Smart City Index in RTHK programmes

Prof. John SHI Wenzhong, Director of Otto Poon Charitable Foundation Smart Cities Research Institute (SCRI), Chair Professor of Geographical Information Science and Remote Sensing, and President of the International Society for Urban Informatics, was interviewed by RTHK’s radio programmes “Hong Kong Today” and “Open Line Open View” to elaborate on the “Smart City Index”. Developed by Prof. Shi and his team, the index aims to help cities worldwide formulate sustainable smart city development strategies. Hong Kong was named second-highest performing Asian city in the rankings at eighth place.   Online coverage: RTHK Hong Kong Today - https://polyu.me/3UlPgO9 (40:28 - 44:01) RTHK Open Line Open View - https://polyu.me/4foflFS (1:06:30 - 1:16:17)

Two PAIR members elected to Young Member Section of Hong Kong Academy of Engineering

Congratulations to Prof. Allen AU Man Ho, Member of Research Institute for Quantum Technology (RIQT) and Professor and Associate Head (Research and Development) of Department of Computing, and Prof. ZHAO Jiong, Member of Research Institute for Advanced Manufacturing (RIAM) and Professor of Department of Applied Physics, on their election as Members of Young Member Section of Hong Kong Academy of Engineering (HKAE). Prof. Au’s research focuses on cryptography, information security and blockchain technology. He has published over 200 papers in leading venues such as CRYPTO, IEEE S&P and ACM CCS. He is a recipient of the BOCHK Science and Technology Innovation Prize in FinTech and the Hong Kong Engineering Science and Technology Award. Prof. Au has won the international ZPrize twice and serves on editorial boards including IEEE TDSC. He is also a member of the HKMA CBDC Expert Group. Prof. Zhao’s research focuses on materials science and engineering, particularly in the areas of electronic materials, nanomechanics, materials synthesis and manufacturing, nanomaterials and nanotechnology. He has made significant contributions to the control and fabrication of ultra-thin films and has pioneered novel techniques for measuring physical properties at the nanoscale. Their election to the Young Member Section is a testament to their outstanding achievements and dedication to advancing engineering research and innovation.

PolyU hosts Global Smart Cities Summit cum the 4th International Conference on Urban Informatics and unveils Smart City Index 2025

The Global Smart Cities Summit cum the 4th International Conference on Urban Informatics, co-organised by the Otto Poon Charitable Foundation Smart Cities Research Institute (SCRI) of The Hong Kong Polytechnic University (PolyU) and the International Society for Urban Informatics (ISUI), commenced yesterday (6 August 2025). The three-day conference brings together over 240 speakers from around the world to share cutting-edge insights and innovations in urban informatics and smart city development, attracting over 600 scholars and industry professionals.  It features keynote speeches by internationally renowned scientists, forums with government and industry leaders, and innovation and technology exhibitions, providing an excellent platform to foster collaborations among government, industry, academia, and research sectors in the field of smart cities. During the event, SCRI and ISUI also jointly announced the ISUI Smart City Index 2025, developed by a team led by Prof. John Wenzhong SHI, Director of SCRI, Chair Professor of Geographical Information Science and Remote Sensing, and President of ISUI.  The Index utilises a human-centric evaluation framework, comprising six dimensions—citizen, environment, social landscape, economy, infrastructure and governance, across 97 indicators.  It adopts an inclusive approach applicable to cities across all development stages—from advanced, to developing and emerging economies, and utilises only publicly available data, giving a broader perspective that enables more relevant and effective policy formulation worldwide. The Index assessed 73 cities worldwide, with the top 10 ranked cities being Stockholm, Washington, D.C., Barcelona, London, Tokyo, Zurich, New York, Hong Kong, Copenhagen, and Oslo.  Hong Kong ranked eighth globally and second in Asia, outperforming major regional competitors such as Singapore, as well as key cities in Europe and North America.  Notably, Hong Kong excelled in the dimensions of environment, economy, and governance. Press release: https://polyu.hk/wtVPG Conference details: https://www.isocui.org/icui2025 Full report of the Smart City Index 2025: https://www.isocui.org/smart_city_index

PolyU research reveals neurocognitive correlates of testosterone in young men that shape generosity and self-worth

A research team led by Prof. WU Yin, Associate Professor of the PolyU Department of Applied Social Sciences and Member of the Mental Health Research Centre (MHRC), has conducted interdisciplinary research to uncover the neurocognitive correlates of testosterone in the brain function of young men, and their impact on social behaviour.  The findings provide valuable insights into potential applications of testosterone therapy in clinical and mental healthcare. Their first study focused on the impact of testosterone on socio-economic behaviour.  The researchers combined pharmacological manipulation and functional magnetic resonance imaging (fMRI) to discover how testosterone influences generosity and the underlying neural mechanisms.  Findings revealed that exogenous testosterone administration reduced generosity, particularly when interacting with more distant others.  Additionally, the fMRI results showed that higher testosterone levels are linked to reduced neural activity in the temporoparietal junction (TPJ), an upper brain region associated with social cognition.  The team suggested that testosterone may reduce concern for others’ welfare at the neural level by dampening activity in the TPJ, highlighting a correlation between increased testosterone levels, and selfishness and reduced empathy in economic decision-making. In another related study, the team explored the link between state self-esteem (SSE), a momentary sense of self-worth and perceived social status, and testosterone levels.  The team found that testosterone administration can boost SSE updating and alleviate aberrant behaviours linked to psychiatric conditions such as anxiety, depression, eating disorders and schizophrenia.  The research indicated that a single dose of testosterone can positively influence SSE, particularly in positive social environments.  It is suggested that future clinical practice consider combining exogenous testosterone with behavioural interventions that foster supportive environments and social feedback to enhance SSE as a potential pre-clinical treatment for relevant aberrant behaviours and clinical symptoms. The two studies have been published in the Proceedings of the National Academy of Sciencesand the Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, respectively.  In recognition of his excellent research, Prof. Wu has been honoured with the Second-class Award under the 9th Higher Education Outstanding Scientific Research Output Awards (Humanities and Social Sciences) by the Ministry of Education of China. Press release: https://polyu.hk/rzWbp   Online coverage: TVB – https://polyu.me/4m2LXYa (00:49 - 01:22) (Chinese only) CRHK – https://polyu.me/4lcj8Y7 (2025-08-05 part 3; 16:44 - 19:09; subscription required) (Chinese only)

PAIR members showcase research at Beijing-Hong Kong-Macao Young Scientists Conference

Dr Gail CHANG, Member of Research Institute for Future Food (RiFood) and Research Assistant Professor in the Department of Food Science and Nutrition; Dr TAO Yong, Member of Research Centre for Resources Engineering towards Carbon Neutrality (RCRE) and Research Assistant Professor in the Department of Civil and Environmental Engineering; and Dr Bruce WANG, Member of Research Institute for Smart Ageing (RISA) and Research Assistant Professor in the Department of English and Communication, showcased their research project outcomes at the Beijing–Hong Kong–Macao Young Scientists Conference held in Beijing on 1 August 2025. At the Conference, Dr Chang shared that mushroom-derived probiotics can not only increase the abundance of Akkermansia muciniphila (AKK) in the gut, but also offer various health benefits such as the prevention of obesity, diabetes and fatty liver disease. Her team is collaborating with various companies to introduce mooncakes, pineapple cakes and ice cream infused with the innovative formula. Dr Tao presented his team’s research on converting waste concrete into green building materials through a newly developed calcination method, thereby saving energy, reducing carbon emissions and improving material performance. Dr Wang shared how his team is using ultrasound imaging technology to study speech disorders and sublingual muscle dysfunction caused by Parkinson’s disease, facilitating innovations in speech therapy. Their projects highlight the research impact of young scientists at PAIR on multiple disciplines, demonstrating the potential of innovative solutions to pressing societal challenges. The Conference provided a valuable platform for knowledge exchange, fostering collaboration among researchers across the globe and paving the way for future advances in health, sustainability and technology.   Online coverage: The Paper - https://polyu.me/4ftzjip Toutiao - https://polyu.me/4ldSPkh

PolyU-developed lunar surface sampling device and Mars camera unveiled at “The Journey of Chinese Aerospace, Aviation and Navigation” exhibition

Jointly organised by the HKSAR Government and the China National Space Administration (CNSA), the “National Development and Achievements Series — Endless Exploration: The Journey of Chinese Aerospace, Aviation and Navigation” exhibition is being held at the Hong Kong Science Museum from 1 August to 7 September 2025. The exhibition features three main zones dedicated to space, aviation and maritime exploration, as well as a Hong Kong zone showcasing the significant contributions by local scientists to national space exploration and deep-sea research. Over one hundred exhibits and installations are on display, and admission is free for all members of the public. The Hong Kong section showcases two innovations developed by the team of Prof. YUNG Kai-leung, Director of Research Centre for Deep Space Explorations (RCDSE), highlighting Hong Kong’s significant contribution to the Nation’s space endeavours. The exhibits include the “Surface Sampling and Packing System”, which and successfully returned lunar soil samples back to Earth in the Chang’e-5 and Chang’e-6 lunar missions; and the “Mars Camera”, which monitored the status of Zhurong rover for the Tianwen-1 Mars mission This exhibition not only allows the public to appreciate the Nation’s latest achievements in aerospace, aviation and maritime technology up close, but also inspires the younger generation’s passion and dreams for scientific exploration, injecting new impetus into Hong Kong’s innovation and technology development. We warmly invite everyone to visit and explore the boundless possibilities of Chinese science and technology.   Online coverage: Ming Pao Daily News - https://polyu.me/4kZZI8J Headline Daily - https://polyu.me/41mdiMF Ta Kung Pao - https://polyu.me/45vuNg4 Wen Wei Po - https://polyu.me/4l4APc8 HK01 - https://polyu.me/4fr1u1B Dot Dot News - https://polyu.me/40MEcgF Hong Kong China News Agency - https://polyu.me/4mlIfZp China Review News - https://polyu.me/41gbbKf Orange News - https://polyu.me/4m2Oy4G hkong.hk - https://polyu.me/4m0mmiK