Chemist with superhuman vision saves the world with photofunctional materials

Mazinger, Getter Robo and Ultraman are superheroes who save the world from monster attacks by harnessing special energy sources—photon energy and solar energy. In some ways, Prof. Wong is like a superhero. He strives to save the world from the energy crisis by playing with atoms and creating photofunctional materials that emit light.

Superhero unleashing the power of science

“I have really liked Ultraman since my youth, and I have continued collecting the toy figures until now. Ultraman accompanied me throughout my childhood,” Prof. Wong recalled. From 2014–2020, he was the first Chinese scientist presented with the Chemistry of the Transition Metals Award by the Royal Society of Chemistry. For seven consecutive years, Prof. Wong has been named in the Clarivate list of Highly Cited Researchers. He is also on the list of top 2% Most-cited Scientists by the Stanford University. The prolific scientist has published more than 800 scientific articles and received numerous awards, including the Croucher Senior Research Fellowship (2009), First Class Prize in Natural Science Award from the Ministry of Education of the People’s Republic of China (2010), FACS Distinguished Young Chemist Award (2011), Ho Leung Ho Lee Foundation Prize for Scientific and Technological Innovation (2012), Second Class Prize in State Natural Science Award of the People’s Republic of China (2013), and the inaugural Research Grant Council (RGC) Senior Research Fellowship (2020/21). Since 2018, Prof. Wong was conferred the Clarea Au Endowed Professorship in Energy in recognition of his devotion to the development of advanced materials for enhanced energy uses.

“Humankind’s quality of life depends on the development of renewable energy sources,” said Prof. Wong. “My research is dedicated to advancing technologies in the conversion of light to electricity and vice versa.” With much of the world’s energy being consumed by lighting needs, the demand for photofunctional materials like photovoltaic cells and organic light-emitting diodes (OLED) has increased. Photofunctional materials are solutions to the problem. Scientists are looking for methods to synthesise these materials.

“The main focus of my work is to develop molecular materials for fabricating organic solar cells and OLEDs. Solar devices produce energy, while light-emitting diodes (LEDs) save energy. So, these developments align with the world’s energy needs,” Prof. Wong explained.

In the past, inorganic LED light sources could support flat screens only. Prof. Wong created low-cost OLED light sources, whose material flexibility makes them compatible with the curved screens of digital displays. These OLED light sources are also preferable to liquid crystal displays (LCDs), as they are more energy-efficient and can be printed onto a surface using an inkjet or even screen-printing technology.

“White organic/polymer light-emitting diodes (WOLEDs/WPLEDs) are environmentally-friendly, energy-saving and low-cost candidates for next-generation illumination sources,” Prof. Wong pointed out. In the year 2009, Prof. Wong and his team first reported a luminous efficiency of up to 20.3 lm/W for a simple single-layer WPLED. This efficiency has recently been improved to 96.3 lm/W at 1000 cd/m². Such propitious progress paves the road to low-cost, large-area WPLEDs, making WPLEDs the choice for power-efficient lighting in the future. Over the years, Prof. Wong has introduced metallic elements with phosphorescence that significantly improve luminous efficiency. He has also introduced a two-colour system, a new alternative to the conventional three-color white light system, to simplify the production of the WPLED devices.

Despite these numerous major breakthroughs, the scientist is continuously aiming for more—higher efficiency and greater sustainability. Currently, Prof. Wong is working on the development of patentable materials for solution-processed OLEDs (s-OLEDs) (funded by CAS–Croucher Funding Scheme for Joint Laboratories) and on long-lived, stable blue OLEDs (funded by National Key Technologies R&D Programme of the Ministry of Science and Technology of China). “Solution-processed OLEDs have high potential to replace conventional liquid-crystal displays and fluorescent tubes for energy-saving applications. They are low-cost, light in weight, flexible for device fabrication, and suitable for large-area manufacturing,” explained Prof. Wong.

The application of OLEDs goes beyond energy savings and electronics. Prof. Wong has been working on fibre-based OLEDs, which emerge from the convergence of fibertonics and textiles. “Luminescent fibre-based displays are still underdeveloped,” Prof. Wong said, “and we plan to develop a series of efficient fibre-based OLEDs which will make full-colour textile displays possible.”

Chemical science for interdisciplinary solutions

Chemistry is a powerful fundamental science. It touches all aspects of our lives. “Chemistry is the essential basis for medicine and public health. It addresses challenges like global climate change as well as our needs for sustainable resources (e.g., clean water, food, energy) and environmental conservation,” said Prof. Wong.

The transcendent nature of chemistry has enabled its extensive applications in interdisciplinary research collaboration. Currently, Prof. Wong is involved in three PAIR constituent research units. In addition to RISE, he is a Member of the Research Institute for Intelligent Wearable Systems (RI-IWEAR) and Research Institute for Sports Science and Technology (RISports). 

At RISE, Prof. Wong has been focusing on Advanced and Renewable Energy Conversion Technologies and Advanced Energy Materials. He is working on metallated graphyne-based two-dimensional nanosheets (funded by the 2020/21 Research Grant Council’s Senior Research Fellowship). “Metallated graphynes (MGYs) represent a new class of photofunctional materials. Through changes to the nanostructures of MGYs, such as their topological structures, pore sizes, surface areas, etc., these materials will exhibit different advanced functions including tuneable optical, electronic and magnetic properties,” he said. The development of MYGs is an interdisciplinary project involving experts in chemistry, physics, and materials science. Prof. Wong anticipates that the project will bring forth a new class of MGY nanosheets with applications in the fields of electronics and catalysis. “All the projects here at RISE involve scientists from different disciplines. We have members who are strong in materials design and synthesis, and other members who provide expertise in device fabrication and engineering. Complementary expertise is crucial to the best outcomes,” said Prof. Wong.

Building an environment for quality chemical research

A scientific spirit includes doing rigorous research and fostering an environment that nurtures scientific rigour. Prof. Wong has been leading the set-up of the first Fourier-transform Electron Paramagnetic Resonance (FT-EPR) spectrometer facility in Hong Kong (funded by the 2021/22 Collaborative Research Fund of RGC). “It will expand the characterisation for molecular and nano-functional materials, since the facility can determine the local and microenvironment of paramagnetic spin-active nuclei, and the electronic communication between these entities within small distances,” Prof. Wong explained.

The new facility marks Prof. Wong’s dedication to improving research quality and steering the Faculty and the University community towards continued improvement. “My responsibility is to support the University in achieving a balanced development among different aspects of the Faculty,” Prof. Wong reflected. “This involves many elements, for example, providing a conducive platform for research by young scientists, facilitating knowledge transfer, and offering a vibrant environment for professional education.”

Looking back at the chemistry journey

With great power comes great responsibility. His dual role as administrator and chemist essentially means that Prof. Wong is handling a double or even greater workload. However, this superman finds purpose in his busy schedule. He believes in the power of research—but this did not occur until he was in graduate school.

“My interest in chemistry became stronger during my postgraduate study at the University of Hong Kong supervised by Prof. Wing-tak WONG, PolyU Deputy President and Provost. I was deeply inspired by my supervisor’s passion for research at that time,” Prof. Wong said, recalling how he was captivated by the intriguing nature of science. “I realised how special and magical scientific research was, and this prompted me to achieve more.”

Looking back at his postgraduate study, Prof. Wong recalled how that journey laid the cornerstone for his success today. “Certain qualities that I developed, such as analytical thinking and creative thinking, are the key factors that help me handle my job well nowadays,” Prof. Wong said. “Patience, diligence, perseverance and confidence are the prerequisites for successful research work.”