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Tag: Hong Kong

E-learning journal co-edited by EdUHK’s professor ranked first for six consecutive years

Posted on by eduhk

The Internet and Higher Education, co-edited by Professor Lim Cher Ping, Chair Professor of Learning Technologies and Innovation at The Education University of Hong Kong, who took over as Editor-in-Chief in 2015, was ranked first again in the e-learning category for the sixth consecutive year (2015 to 2020), according to the latest SCImago Journal Rank.

Under the Education category, the journal has been ranked consistently in the top 15. The 2021 Journal Citation Reports of Clarivate Analytics showed that the journal was ranked fifth by the Journal Impact Factor (7.178) in the Education and Educational Research category, and was ranked second by the Journal Citation Indictor (5.01) in the same category.

EdUHK Dr Winnie Lam’s online evidence-based assessment system for student group activities

Posted on by eduhk

Undergraduate students usually need to collaborate with others to complete various types of group projects. However, it is not easy to distribute the work evenly among the group members, and some members are even called “free riders” because of their small contributions to the project.

As a result, teachers usually receive complaints at the end of the semester on this issue. In view of this, Dr Lam Wai-man at the Department of Mathematics and Information Technology of The Education University of Hong Kong developed an Online Evidence-based Assessment System called GMoodle for collaborative learning.

Instead of assessing the final outcome, the process of collaboration is recorded. Students can keep track of the progress of individuals and their group members in GMoodle. Whereas teachers can make use of the progress report to set assessment criteria and identify free riders.

As it is not easy to ensure all students are actively and equally contributed and collaborate with each other in group projects, this system can provide an objective measure to reflect the actual contribution and activeness of each student. It is also useful for students to review their learning goals.

Besides, each student has an individual GMoodle account to store their own learning activities. Once they have logged in the platform, they can view their contribution scores and compare theirs with the average in class to understand their learning progress is on track or not. Most importantly, students can make use of the discussion forum, chat room and Wiki report to create a proactive collaborative learning environment.

GMoodle has been recognised for its innovation and creativity. It obtained the Silver Medal and Special Award – Special Inventor Award in the International Invention Innovation Competition in Canada in 2019. Riding on the success, Dr Lam invited other external parties to collaborate for further development and improvement of the platform.

Future developments in the pipeline include incorporating AI and data mining to customise learning materials, applying to multi-disciplinary courses, adding more collaborative tools, adding co-teaching features, and launching in secondary schools.

BOC–HKBU Chinese medicine community scheme offers free rehabilitation services to low-income stroke patients

Posted on by HKBUCPRO

Hong Kong Baptist University (HKBU) and the Hong Kong Sheng Kung Hui (HKSKH) Welfare Council have received a generous donation from the Bank of China (Hong Kong) (BOCHK) for the three-year “BOC–HKBU Chinese Medicine Community Stroke Prevention and Rehabilitation Scheme”.

The Scheme provides free Chinese medicine rehabilitation treatments to 500 eligible low-income stroke patients and it also offers free preventive treatments and tracking assessments to 1,200 people who have a medium to high risk of having a stroke.

The launch ceremony for the Scheme was held on 29 July on the HKBU campus. Dr Cheung Wai-lun, Project Director of the Chinese Medicine Hospital Project Office, the Food and Health Bureau; Mr Jimmy Sun, General Manager of the Institutional Business Department, BOCHK; Professor Alexander Wai, President and Vice-Chancellor of HKBU; and Dr Lee Ching-yee, Director of HKSKH Welfare Council Limited, officiated at the ceremony.

In his speech, Professor Alexander Wai said the School of Chinese Medicine (SCM) at HKBU launched Hong Kong’s first full-time Chinese medicine undergraduate programme funded by the University Grants Committee in 1988. Since then, SCM has been providing Chinese medicine services to the community and promoting Chinese medicine education, research and healthcare services in Hong Kong.

“Apart from reducing public healthcare expenses, improving the quality of life of stroke patients, and increasing the success rate of rehabilitation initiatives, the BOC-HKBU Chinese Medicine Community Stroke Prevention and Rehabilitation Scheme can also serve as a good example of how we can construct a community medical service management model based on collaboration between the Chinese medicine sector and the community,” he said.

Mr Jimmy Sun said: “BOCHK has all along taken a proactive approach to its social responsibilities, and it has continuously supported primary healthcare and the development of Chinese medicine. We have maintained a long-term partnership with HKBU in the area of Chinese medicine, including a donation to its School of Chinese Medicine to establish the Bank of China (Hong Kong) Chinese Medicines Centre in 2003, and the offering of Chinese medicine supplements for pneumonia prevention to frontline medical staff in collaboration with the University’s Anti-SARS Action Group in the fight against the SARS outbreak. In the future, BOC will continue to support the development of Chinese medicine so that more Hong Kong citizens can benefit.”

Dr Lee Ching-yee said the HKSKH Welfare Council has worked with SCM through a medical-community collaboration to set up community clinics since 2017. In particular, teachers and students from SCM visited elderly people in the Kowloon City district to follow up and deal with their physical pain problems. “The community clinics set up by this Scheme officially opened in January this year. In just half a year, the project team received more than 100 applications. With professional treatments administered by Chinese medicine practitioners and follow-ups organised by social workers, many successful cases have been observed,” she said.

Mr Wong Hon-kwong, a beneficiary of the Scheme who received half a year of free Chinese medicine and acupuncture services, said: “I could not open my left palm before, but I can now. My friends can see my progress.” His wife also said that he has improved his mobility. As a result,  he can now walk more smoothly, and these developments have boosted his self-confidence.

The BOC–HKBU Chinese Medicine Community Stroke Prevention and Rehabilitation Scheme, which started in October 2020 and runs until September 2023, mainly serves people aged 60 or above who are Comprehensive Social Security Assistance or Old Age Living Allowance recipients, or stroke patients from low-income families. Stroke patients under the age of 60 who are in need of support can also join the Scheme after an assessment by social workers or a referral from one of the SCM clinics.

Under the Scheme, experts from SCM will form treatment teams and formulate a six-month treatment programme for stroke patients.

Patients will receive free Chinese medicine, acupuncture and massage treatments two to three times a week, up to 72 times in total. SCM will arrange for Chinese medicine practitioners to visit the patients, or alternatively, the practitioners will invite them to receive their treatments at the elderly centres of the HKSKH Welfare Council. It is expected that about 500 people will benefit from the Scheme. Furthermore, the Scheme will provide counselling and support services for older stroke patients and their family members.

In addition, SCM clinics and the HKSKH Welfare Council’s elderly centres will set up health management stations for stroke patients, with SCM offering training to suitable older people who can then go on and serve as Chinese medicine senior ambassadors for stroke prevention. Using a soon-to-be-launched website, the ambassadors will assess the risk of stroke in other older people in the community and promote stroke prevention messages.

Around 1,200 older people with a moderate to high risk of stroke will be referred to the HKSKH Welfare Council’s elderly centres to undergo a one-year preventive treatment programme and follow-up assessments. The website will also provide recommendations on balanced diets and appropriate exercises for people with a low to medium risk of stroke, and alert high-risk individuals to seek medical treatment.

Those who are interested in participating in the Scheme can call 6533 9972 or 2333 1854 for any enquiries, or they can complete the following online form: https://docs.google.com/forms/d/e/1FAIpQLSdCoJwAYWDzOpxXvzkOYkRx0_7xB8GvZeuscb7B98jtiwItGA/viewform

EdUHK Scholar studies COVID-19-related stress and mental health problems of parents

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COVID-19 not only threatens people’s physical health, but also creates disruption in work and social relationships. Parents experience additional strain resulting from extra childcare responsibilities. This is even more pronounced with parents of children with developmental disorders, which calls for the need for increased parenting support services and family-friendly policy initiatives in Hong Kong.

Dr Randolph Chan Chun-Ho, Associate Head and Assistant Professor at the Department of Special Education and Counselling, The Education University of Hong Kong (EdUHK) conducted a study to (1) investigate and compare the prevalence of COVID-19-related stress and mental health problems between parents of children with developmental disorders and those of children with typical development, and (2) examine the association of COVID-19-related stress with mental health problems.

In May 2020, the study recruited 129 parents of 8-to-10-year-olds, with either developmental disorders or typical development, from 12 mainstream primary schools in Hong Kong.

It was found that close to 75% of the parents indicated that their work and social lives had been significantly disrupted because of the social-distancing measures in Hong Kong. When schools were closed, children had to stay at home, meaning parents had to reorganise childcare. Nearly two-thirds of the parents reported significant difficulty in taking care of their children and experienced strain trying to balance the demands of childcare and work. More than half of the parents expressed concern about the risk of them and their children being infected with COVID-19.

The findings showed that parents of children with developmental disorders are at greater risk of parenting stress than parents of children with typical development. The parents of children with developmental disorders showed more severe symptoms of depression and anxiety than their counterparts. 25% of them met the criteria for clinical depression, and 13.7% met the criteria for generalised anxiety disorder. Parenting stress during the COVID-19 pandemic explained heightened levels of mental health problems among parents of children with developmental disorders as compared to parents of children with typical development.

Given the elevated risk of parenting stress and mental health problems observed among parents of children with developmental disorders, the study recommends timely positive parenting support to reinforce parent-child relationships, alleviate parents’ psychological distress, and help them cope with health worries and parenting stress. In addition to parenting programmes to enhance competence and efficacy, web-based skills programmes can be offered to parents who are in need of professional support and guidance. Online counselling and support group services, and family friendly policies can also help parents have a more balanced life during this critical time.

The research has been published in Journal of Autism and Developmental Disorders, please visit here for details.

EdUHK Scholar co-authors article published in Nature Climate Change

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A team of leading climate social scientists, including a chair professor at The Education University of Hong Kong (EdUHK), argues that influential studies that attempt to quantify different countries’ “fair shares” of climate action have put forward a biased and oversimplified view of what is primarily a political and ethical discussion.

The Perspective piece, “Ethical choices behind quantifications of fair contributions under the Paris Agreement,” published in the pre-eminent academic journal Nature Climate Change, comes as the world’s governments are expected to release new national plans for climate action ahead of climate negotiations later this year in Glasgow, Scotland, and defend them as “fair and ambitious”.

One of the article’s co-authors is Professor Paul G. Harris, Chair Professor of Global and Environmental Studies in the Department of Social Sciences at EdUHK, who has spent three decades conducting research and writing about climate justice and governance.

The piece evaluates a selection of recent effort-sharing studies to determine whether they are explicit about the ethical choices underlying their analyses. Reviewing sixteen studies that quantify equitable effort sharing between countries under the Paris Agreement, the authors find that nearly two-thirds (10 studies) present themselves as neutral or value-free, despite being limited to a small and biased subset of ethical perspectives on effort-sharing that tend to favour wealthier countries.

“It is widely assumed that climate change is a technical or political problem. It is more accurate to conceive of it as a normative problem in which disagreements about what is just, fair and equitable crowd out co-operation on social and technological solutions,” said Professor Harris.

Sivan Kartha, Senior Scientist at the Stockholm Environment Institute added, “Studies that incorrectly purport to be neutral and objective are not just misleading, they can even be harmful. In this case, they can set unrealistic expectations about what countries might be expected to contribute to a global climate effort. Even if it’s not intentional, one can imagine the problems caused by a body of literature with a consistent bias toward wealthier and against poorer countries.”

In particular, the ‘grandfathering’ of emissions, where countries argue their status as high emitters is a justification for continued high emissions, should not be included in equity assessments of global climate action. This is a key source of the systematic bias in favour of wealthier, higher emitting countries.

Other studies claim objectivity by averaging a spectrum of equity approaches, commonly choosing a subset that excludes important ethical concepts. For instance, when many analyses quantify a country’s capacity to allocate resources to a global climate effort, they routinely treat a dollar earned by a poor citizen as wholly equivalent to a dollar earned by a rich citizen.

Many indicators ranking nations’ efforts to address climate change “say they’re about equity, but there’s still a systematic bias in favour of the biggest historical polluters. As we review efforts in the ‘global stocktake’ of the Paris Agreement, these kinds of indicators must be transparent.  Otherwise, they are anti-equity,” said Timmons Roberts, Professor of Environmental Studies and Sociology at Brown University and Director of the Climate Social Science Network.

“Studies should be explicit about the ethical and moral implications of their underlying assumptions, and equity assessments of countries’ climate action must be based on ethically defensible principles, such as responsibility, capacity and need,” said Dr Kate Dooley, Research Fellow at the University of Melbourne and lead author of the study.

Professor Harris added: “This article helps to reinforce what we already know from other aspects of life: reliance on statistical indicators can result in potentially unjust outcomes. It’s more important than ever to view the ethical challenges of climate change holistically and qualitatively.”

The authors propose new guidelines that emphasise transparency in communicating the ethical underpinnings of assessments of climate action and suggest guidelines for developing policy-relevant — but not ethically neutral — equity research, which includes studies of equitable distribution of climate efforts should not claim value-neutrality; analysis needs to ensure that the losses of those who are potentially marginalised remain clearly visible, and analytical work should aim to inform rather than supplant the political process.

HKBU secures funding from RGC Theme-based Research Scheme to build platform technologies for symbiotic creativity

Posted on by HKBUCPRO

A research project led by Hong Kong Baptist University (HKBU) titled “Building Platform
Technologies for Symbiotic Creativity in Hong Kong” has been awarded HK$52.8 million in research funding from the Theme-based Research Scheme (11th round) under the Research Grants Council (RGC) for a five-year project. This is the first time that major funding has been allocated by the RGC for an art-tech project.

The research team will develop platform technologies for symbiotic creativity, providing unlimited art content for humans, including an art data repository, an artificial intelligence (AI) creative algorithm system, a research theatre, a digital art and policy network, and some unique and creative application projects, to usher in a new era of the art technology.

 Led by Professor Guo Yike, Vice-President (Research and Development), and Professor
Johnny M Poon, Associate Vice-President (Interdisciplinary Research), at HKBU, the research team will develop an immersive and interactive extended reality (XR) platform to capture human data during the artistic creation and appreciation process, which includes the cognitive and physiological data of artists and the audience, such as brain waves, body temperature and heart rates, gait and movements, etc. The platform will then convert the data into the descriptors of cognition, emotions, and behavioural patterns.

The researchers will associate and link the artworks with the descriptors to build a comprehensive and extensive data repository for artificial intelligence model training. It will enable machines to learn human aesthetics, instead of mimicking art created by humans.

 The platform will also enable the audience to immerse themselves in a virtual world. They will be surrounded by images, sounds, etc, and have new artistic experiences. In addition, the immersive and interactive XR platform will be equipped with a number of sensing devices, which will help the artists to go beyond the traditional forms and boundaries and communicate and interact with the audience in new ways.

“This research project has secured funding from the RGC, demonstrating that Hong Kong
attaches great importance to the development of artistic and creative technologies based on AI. This project stands at the forefront of the arts and science nexus, harnessing the power of science and technology to advance human and AI interaction in art creation. It will foster a new direction in art created by both humans and machines,” said Professor Guo.

 “We will spare no effort in building a world-class AI art creation platform, and it will
drive a new revolution that transforms the creative and cultural industries. It
will enable Hong Kong to assume a leading position in art-tech on the global stage,”
he added.

 Under this project, HKBU will launch three application projects: the Super AI artist – the
world’s first “Combined Music and Art Biennale”, which will host multidisciplinary musical works and artworks jointly created by humans and AI; Shared Mind and Empathetic AI – a concert series featuring a three-way collaboration between performers, the audience and machines; and Symbiotic Opera – a new form of opera that integrates with immersive XR technology, and it will be jointly created by humans and machines in an immersive virtual
world.

 Members of the multidisciplinary research team led by HKBU include cognitive scientists,
AI and data scientists, media scientists, ethicists and art policy scholars from Yale University, the University of Cambridge, Imperial College London, the University of Kent, Tsinghua University, the University of Hong Kong and City University of Hong Kong. The research team will also collaborate closely with industrial and musical partners, including Huawei, Microsoft, SenseTime and Opera Hong Kong. 

EdUHK scholar develops intervention to promote health and fitness

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Urbanisation, technological advances, and increasing convenience in everyday life have restricted the amount of physical exercise most people engage in, resulting in major public health concern. This persistent and growing health-related problem calls for an acute need to develop an intervention programme that can effectively promote physical activities, not only at the individual level but also at the family, community, and citywide levels.

Whether positive psychology concepts can be integrated with health-promotion behaviours among families had largely been unknown until researchers in Hong Kong developed a positive physical activity (PPA) intervention. This has been made possible by using the positive psychology concepts of joy, gratitude, and savouring to promote Zero-Time Exercise (ZTEx) (which involves integrating simple physical activities into everyday life) and improve physical fitness in Hong Kong families.

Dr Henry Ho Chun-yip, Assistant Professor at the Department of Psychology of The Education University of Hong Kong (EdUHK), together with other researchers and healthcare professionals, worked with different stakeholders during the study, including the government, social service organisations and schools. A cluster randomised controlled trial was conducted with 1,983 participants in 1,467 families in Hong Kong. Data were collected using structured questionnaires and physical fitness assessments before the intervention and in follow-ups one and three months after the trial.

Social workers and teachers of the participating organisations and schools were trained to design and implement the community programmes. The training workshop was delivered by clinical psychologists, registered social workers, registered nurse, and academic researchers to comprehensively cover the contents of positive psychology, physical activity, programme design and programme evaluation.

The study measured the self-reported frequency of ZTEx both alone and with family members and assessed balance and endurance as indicators of physical fitness. It found that PPA intervention was effective in increasing ZTEx with both groups in each time periods, and in improving balance and endurance in the three-month follow-up.

Semi-structured focus groups added in-depth insights into the participants’ motivational, interpersonal and affective experiences. The findings showed that PPA intervention is a cost-effective way to improve physical activity and fitness and that a community-based collaborative approach was successful in engaging community stakeholders in an active and fruitful partnership for programme development.

The findings support the proposition that health promotion behaviour is maintained when the participants experience positive emotions during the activities. Through the application of positive psychology, the participants associated ZTEx with feelings of enjoyment, which nurtured unconscious motives for this health promotion behaviour, thus leading to a successful lifestyle change and improved physical fitness.

This study has important implications for Hong Kong, where 71% of adults did not meet the WHO physical activity recommendations.

EdUHK Scholar’s recently published study covers humans’ historical adaptation to climate change

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A research team including a scholar from The Education University of Hong Kong (EdUHK) has given a new perspective into human adaptation to climate change. The study’s findings were recently published in the prestigious academic journal Nature.

Climate change is an important issue which has been extensively discussed over the past years. While many experts believe that climate change has had a profound impact on human history, to date there has been little discussion about how humans have reacted to these altering circumstances.

With this in mind, a research team of 18 experts from different countries and disciplines undertook a study to understand the interplay between what they have called “History of Climate and Society”. The team sought to examine the role of human resilience to climate change in shaping human history and the complex connection between them.

Led by Dr Dagomar Degroot from Georgetown University, the research team comprised 18 scholars from the Germany, Poland, Switzerland, United Kingdom, United States, mainland China and Hong Kong. Their expertise covers geography, archaeology, history to paleoclimatology. Among the team was Dr Pei Qing, Assistant Professor of the Department of Social Sciences at EdUHK, who contributed to revising the design and framework of the entire study.

To understand the effect of climate change on human history, the team selected different societies across continents for case analysis covering two climatic eras: the Late Antique Little Ice Age around the 6th century; and the Little Ice Age from the 13th century to the 19th century. Among these cases, Dr Pei also contributed to the Asia case study – the rise of the Jianzhou Jurchens during the early 17th century – in collaboration with Dr Cui Jianxin from the Northwest Institute of Historical Environment and Socio-Economic Development of Shaanxi Normal University.

The pair found that although both the Jianzhou Jurchens and the Ming Dynasty were affected by drought through monsoon failure, the former thrived and survived because of their higher mobility, thanks to their tradition of hunting and gathering. This enabled them to adapt through encroaching on cultivated land to the south and controlling trade networks.

The interdisciplinary team also looked into how, in the 6thcentury, people in the Middle East under Roman rule made use of the humid climate to cultivate and expand their territory; how, in 13thcentury, the governments of Bologna and Siena used strategies like food regulations to deal with natural disasters and minimise famine and mortality; and how, in the 17th century, Dutch sailors took advantage of precipitation and prevailing winds to defend themselves against Spanish invasion. These cases showed how human resilience to climate change could help explain the rise and fall of different political regimes or dynasties in human history.

Dr Pei said, “Many studies in the past have demonstrated the impact of historical climate change on human societies, particularly on a long-term and large spatial scale. However, our study provides a new perspective for academic research, indicating that the communities could effectively respond to the challenges of climate change.”

According to Dr Pei, historical cases also tell us that successful adaptation to climate change usually depends on the ability of a community to control or capitalise resources.

Dr Pei pointed out that this study provides insights for the public to reflect upon the resilience of different peoples against climate change. “When a country acts to deal with changing climatic conditions, its measures may bring a negative influence to other countries. When formulating climate actions or related policies, countries should not only consider their own benefits, but also their neighbours, and even the whole world, so as to pursue and realise the equitable principle of combatting climate change.”

The study also uncovered several common criteria of historical societies that coped well with climate change, including strong trade networks, high mobility and the capacity to learn from mistakes. “Human societies’ evolving resilience and historical successes have given us confidence in dealing with global warming. However, we should also carefully consider our relationship with nature and learn the lessons from our history,” Dr Pei said, adding that he hoped this study would provide a solid academic foundation for the scholars to better explore the relationship between historical climate change and human societies in the future.

The original publication can be found in Nature.

CityU develops advanced robot sensors to facilitate superior touch and feel

Posted on by Editorial Team

By mimicking human skin, new kinds of tactile sensor technologies created at the City University of Hong Kong (CityU) offer hope to improving the quality of life for people suffering serious injuries and disabilities.

These breakthrough technologies, developed through two research projects co-led by CityU, are so sophisticated that they enable a robotic appendage to behave like a human hand and complete such tasks as threading a needle or grasping a fragile piece of tofu without spillage.

In the first project, Dr Shen Yajing, Associate Professor in CityU’s Department of Biomedical Engineering, has co-led joint research with the University of Hong Kong on developing a new kind of soft sensor with skin-comparable characteristics.

The research, published in Science Robotics under the title “Soft magnetic skin for super-resolution tactile sensing with force self-decoupling”, promises to advance areas such as the development of smart prosthetics and human–robot interaction.

The sensor is located in a multi-layered structure modelled on human skin. A very special feature is that the sensor can “decouple”, or decompose, the external force automatically into two components, providing an accurate measurement of these two forces respectively in order to analyse or control the stationary or moving state of an object.

Moreover, tactile “super-resolution” allows the sensor to accurately locate the stimuli’s position. “Our efficient tactile super-resolution algorithm uses deep learning and has achieved a 60-fold improvement in the localisation accuracy of the contact position, which is the best among super-resolution methods reported so far,” said Dr Shen.

“To the best of our knowledge, this is the first tactile sensor that has achieved self-decoupling and super-resolution abilities simultaneously,” he added.

By mounting the sensor at the fingertips of a robotic gripper, the team has demonstrated that robots can accomplish challenging tasks. For example, the robotic gripper can grasp fragile objects like an egg with a high degree of stability while an external force is trying to drag it away, and it can thread a needle via teleoperation.

“This proposed sensor can help develop adaptive grasping, dexterous manipulation, texture recognition, smart prosthetics and human–robot interaction. The advance of soft artificial tactile sensors with skin-comparable characteristics can make domestic robots a future reality in our daily life,” Dr Shen added.

Inspired by the delicate structure of human skin, the second research project, this time co-led by Dr Yang Zhengbao, Assistant Professor in the Department of Mechanical Engineering, has created a highly sensitive tactile sensor array that has the potential to restore touch and sensation, as well as monitor health.

Consisting of protective layers, an insulative layer and two piezo sensory layers, the dual-layer comb piezoelectric tactile sensor array that the team fabricated can measure more spatiotemporal information than similar technologies. Furthermore, the team invented the “row+column” electrode structure that can reduce fabrication costs significantly.

“The system can achieve real-time detection and differentiation of diverse external stimuli such as bending, tension and compression within one sensor element. Our sensor can respond extremely fast, with a response time down to 10 milliseconds, which is even faster than human skin,” Dr Yang explained.

The tactile sensor is so delicate that it can even grasp a fragile piece of tofu without breakage, showing great potential for the human–machine interface and promoting the development of smarter prosthetics, robotic hands, and equipment for handling multiple soft and fragile products in industry.

The system is a promising candidate for reconstructing the human tactile system, i.e. re-establishing tactile sensation for people with skin damage and assisting amputees. The sensor can also help monitor overall human health, for example by accurately detecting weak artery pulses.

The team’s findings have been published in Advanced Science under the title “Skin-inspired piezoelectric tactile sensor array with crosstalk-free row+column electrodes for spatiotemporally distinguishing diverse stimuli”.

CityU scientists produce efficient LEDs based on 2D perovskite material

Posted on by Editorial Team

The use of a simple organic molecule during the fabrication of a two-dimensional (2D) perovskite results in one of the highest recorded efficiencies for perovskite-based devices. Light-emitting diodes (LEDs) employing this 2D perovskite material achieved an external quantum efficiency as high as 20.5%, which rivals the best organic LEDs, according to research co-led by the City University of Hong Kong (CityU).

Led by Professor Andrey Rogach, Chair Professor at the Department of Materials Science and Engineering, CityU, and his collaborator Professor Yang Xuyong from Shanghai University, the research team has worked on 2D perovskite materials and succeeded to realise such efficient and bright green LEDs.

Their technology yielded the best-reported performance on both current efficiency and external quantum efficiency. This work has now put the perovskite LEDs close on the heels of current commercial display technologies, such as organic LEDs.

The findings were published in the scientific journal Nature Communications, titled “Smoothing the energy transfer pathway in quasi-2D perovskite films using methane sulfonate leads to highly efficient light-emitting devices”.

The key to the powerful change lies in the addition of around 10% of a simple organic molecule, called methanesulfonate (MeS). This molecule reconstructs the structure of the 2D perovskite nanosheets, while simultaneously enhancing exciton energy transfer between sheets of different thicknesses. It is also useful in reducing defects in the 2D perovskite structure, contributing to higher efficiency.

The consequences for producing better LEDs are encouraging. Brightness of 13,400 candela/m2 at a low applied voltage of 5.5 V, and an external quantum efficiency 20.5% is recorded. This is close to the maximum that can be achieved by many existing LED technologies and has almost doubled the external quantum efficiency level of 10.5% reported in the previous collaborative study of the same groups two years ago.

“The CityU team has built up its expertise on perovskite materials to a very high level in a relatively short period of time, thanks to funding support from Senior Research Fellowship by the Croucher Foundation,” said Professor Rogach.

“The high brightness, excellent colour purity, and commercial-grade operating efficiency achieved marks 2D perovskites as an extremely attractive material for future commercial LEDs, and potentially also display technology. It’s a tangible outcome from both fundamental and applied research into novel nano-scale materials” he adds.