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Taming AI: Engineering, Ethics, and Policy
(Professor Lee, Professor Koene, Professor Walsh, and Professor Ema (from left)) Can AI-powered robotics could be adequate companions for humans? Will the good faith of users and developers work for helping AI-powered robots become the new tribe of the digital future? AI’s efficiency is creating new socio-economic opportunities in the global market. Despite the opportunities, challenges still remain. It is said that efficiency-enforcing algorithms through deep learning will take an eventual toll on human dignity and safety, bringing out the disastrous fiascos featured in the Terminator movies. A research group at the Korean Flagship AI Project for Emotional Digital Companionship at KAIST Institute for AI (KI4AI) and the Fourth Industrial Intelligence Center at KAIST Institute co-hosted a seminar, “Taming AI: Engineering, Ethics, and Policy” last week to discuss ways to better employ AI technologies in ways that upholds human values. The KI4AI has been conducting this flagship project from the end of 2016 with the support of the Ministry of Science and ICT. The seminar brought together three speakers from Australia, Japan, and the UK to better fathom the implications of the new technology emergence from the ethical perspectives of engineering and discuss policymaking for the responsible usage of technology. Professor Toby Walsh, an anti-autonomous weapon activist from New South Wales University in Australia continued to argue the possible risk that AI poses to malfunction. He said that an independent ethics committee or group usually monitors academic institutions’ research activities in order to avoid any possible mishaps. However, he said there is no independent group or committee monitoring the nature of corporations’ engagement of such technologies, while its possible threats against humanity are alleged to be growing. He mentioned that Google’s and Amazon’s information collecting also pose a potent threat. He said that ethical standards similar to academic research integrity should be established to avoid the possible restricting of the dignity of humans and mass destruction. He hoped that KAIST and Google would play a leading role in establishing an international norm toward this compelling issue. Professor Arisa Ema from the University of Tokyo provided very compelling arguments for thinking about the duplicity of technology and how technology should serve the public interest without any bias against gender, race, and social stratum. She pointed out the information dominated by several Western corporations like Google. She said that such algorithms for deep learning of data provided by several Western corporations will create very biased information, only applicable to limited races and classes. Meanwhile, Professor Ansgar Koene from the University of Nottingham presented the IEEE’s global initiative on the ethics of autonomous and intelligence systems. He shared the cases of industry standards and ethically-aligned designs made by the IEEE Standards Association. He said more than 250 global cross-disciplinary thought leaders from around the world joined to develop ethical guidelines called Ethically Aligned Design (EAD) V2. EAD V2 includes methodologies to guide ethical research and design, embedding values into autonomous intelligence systems among others. For the next step beyond EAD V2, the association is now working for IEEE P70xx Standards Projects, detailing more technical approaches. Professor Soo Young Lee at KAIST argued that the eventual goal of complete AI is to have human-like emotions, calling it a new paradigm for the relationship between humans and AI-robots. According to Professor Lee, AI-powered robots will serve as a good companion for humans. “Especially in aging societies affecting the globe, this will be a very viable and practical option,” he said. He pointed out, “Kids learn from parents’ morality and social behavior. Users should have AI-robots learn morality as well. Their relationships should be based on good faith and trust, no longer that of master and slave. He said that liability issues for any mishap will need to be discussed further, but basically each user and developer should have their own responsibility when dealing with these issues.
2018.06.26
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The 8th KINC Fusion Research Awardees
The KAIST Institute for NanoCentury held the 8th KINC Fusion Research Award in order to encourage professors’ convergence studies and instill students’ willingness to research. The award ceremony took place in the KI Building at KAIST on March 13. The KINC Fusion Research Award selects the most outstanding convergence studies among research undertaken last year, and awards researchers who participated in that research. The 8th KINC Fusion Research Award went to Professor Yoon Sung Nam from the Department of Materials Science and Engineering and Professor Inkyu Park from the Department of Mechanical Engineering. Their research reported the spontaneous self-biomineralization of palladium (Pd) ions on a filamentous virus to form ligand-free Pd nanowires without reducing reagents or using additional surface stabilizers (Title: Virus-Templated Self-Mineralization of Ligand-Free Colloidal Palladium Nanostructures for High Surface Activity and Stability, Advanced Functional Materials (2017)). Professor Hee-Tae Jung, the Director of KAIST Institute for the NanoCentury and the host of the KINC Fusion Research Award said, “Convergence will be the crucial keyword that will lead to revolutionary change. Hence, the importance of convergence study should be improved. We will put every effort into creating a research environment for increasing convergence study. The KAIST Institute for the NanoCentury was established in June 2006 under the KAIST Institute with a mission of creating convergence study by tearing down boarders among departments and carrying out interdisciplinary joint research. Currently, approximately 90 professors from 14 departments participate the institute. It aims to become a hub of university institutes for nano-fusion research.
2018.03.19
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President Shin Reaffirms Innovation Initiatives in New Year Speech
(President Shin and representatives of faculty, students, staff celebrate the New Year in a reception held on January 2 at the auditorium.) The KAIST community gathered to celebrate a fresh start for the year 2018. At the ceremony, held in the auditorium on January 2, members of KAIST community reaffirmed their commitment to be the trailblazers of Korea and beyond through unwavering innovations. President Sung-Chul Shin presented his new vision and plan in his New Year speech, which focused on innovation for enhancing institutional competitiveness and global visibility. He said that as you are the future of KAIST, KAIST is the future of Korea. KAIST’s vision for a better future will have a significant impact on national progress and beyond. He stressed that innovation in the five pillars of education, research, technology commercialization, globalization, and future strategy will further advance the excellence of KAIST. At the ceremony, President Shin also presented the award for ‘the KAISTian of the Year’ to Professor YongKeun Park of the Department of Physics. The annual award recognizes a distinguished professor whose academic accomplishments made the most significant impact. In his New Year speech, President Shin said that the year 2018 will provide an opportunity to take a leap forward for becoming a ‘Global Value Creative, World-Leading University. The Vision 2031 Committee endorsed the five innovation initiatives to fulfill KAIST’s long-term vision and will open its recommendations to the public on March 20. Educational innovation tops the initiatives. President Shin explained that the future of Korea is in the hands of talented individuals in science and technology, emphasizing the need to nurture creative, transdisciplinary talents with the capacity to enhance the social value of science and technology. To this end, KAIST will establish a new undergraduate non-departmental program for transdisciplinary education. This plan will eventually provide students with more options in choosing their major, as well as help students build a strong foundation in basic science and engineering and encourage multidisciplinary approaches. For creating an innovative institutional research infrastructure, KAIST plans to build a Network of Excellence for the Fourth Industrial Revolution (NExFire) for convergence research. The plan of ‘Cross-Generational Collaborative Labs,’ will bring out a new collaboration platform by pairing up senior and junior faculty. President Shin said it will be a stepping stone to extend the spectrum of knowledge without any cessation. For technology commercialization, KAIST will maximize its intellectual property and economic value by stimulating technology-invested companies and startups. Close cooperation with venture capitalists at home and abroad will further accelerate the commercialization drive at KAIST. Saying that the globalization is no long an option but a necessity, he stressed KAIST will strengthen its efforts to established a bilingual campus. “KAIST will make every effort to create a more welcoming and comfortable atmosphere for the international community and their families. We will expand benefits to our international community, such as access to the KAIST Child Care Center and collaboration with the Taejon Christian International School (TCIS),” he said. President Shin added he will further expand global networks and partnerships this year, participating in a diverse range of international events at home and abroad for increasing global visibility. He also said that well-designed future strategies will complete innovation initiatives. The Future Strategy Research Center will serve as a think tank for identifying future agendas, establishing strategies and advocating for them. In addition to the five innovation initiatives, President Shin emphasized a new organizational culture that embraces inclusiveness and mutual respect among all of the members of KAIST. “So far, the ideal qualifications expected of KAISTians have included creativity and a challenging spirit. From now on, we will nurture talents with a focus on the 3Cs: Creativity, Challenge, and Caring. I would like to make a campus in which all members care for each other to help attain mutual growth with warmth and respect," he said. For the full text, Click
2018.01.02
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Seoul Climate-Energy Conference Seeks Global Sustainability
(President Shin and Former UN Secretary General at the Seoul Climate Change-Energy Conference) Global leaders from both the private and public sectors discussed creative ways to seek inclusive green growth and sustainable development at the Seoul Climate-Energy Conference on November 24 in Seoul. The annual conference was co-hosted by KAIST and the Coalition for Our Common Future under the theme “Creating New Momentum for the Paris Agreement and a Sustainable Future.” More than 100 global leaders participated in the forum including the Director General Frank Rijsbermanof the Global Green Growth Institute and Executive Director Howard Bamsey of the Green Climate Fund. Former UN Secretary-General Ban Ki-Moon, who played a significant role in the signing of the Paris Agreement, was the keynote speaker. This year’s conference focused on Korea’s low carbon-energy transition and the Fourth Industrial Revolution to be aligned with green growth. At the conference, speakers and participants reviewed the progress of the decisions made by the UN Framework Convention on Climate Change (UNFCCC) COP23 in Bonn, Germany. The conference discussed topics of global collaboration for new climate regimes, green energy infrastructure, the Asia super grid, financing green energy, smart green cities, and new mobility. President Sung-Chul Shin emphasized global action and greater resilience toward climate change in his opening remarks. He said, “Today’s climate change can be attributed directly to the past three industrial revolutions. As industrialization continues, we must not make future generations pay the cost of this Fourth Industrial Revolution.” He explained that it is increasingly complicated to address climate change and energy issues because even though the use of energy consumption will continue to increase, energy policies are interwoven with global politics. He stressed three keywords to better address this global problem: innovation, collaboration, and speed. First he emphasized innovation as a priority for future success as it is hard to retain confidence without innovation. He noted KAIST has made sustainability initiatives in the fields of EEWS (energy, environment, water, sustainability) and green mobility. He also noted the importance of collaboration as industries are moving beyond a single discipline. KAIST is making collaborations in R&D and sustainability sectors, such as Saudi Aramco’s CO2 management center in KAIST. Finally, he explained that the speed of new transformation will be beyond our imagination, and governments should work efficiently to address issues in a fast manner. Meanwhile, Secretary-General Ban called for global unity in addressing climate change. He strongly emphasized that countries should make agreements not of willingness but of action, and that politicians should realize that this global agenda should be given top priority above domestic politics. He addressed how the world is experiencing the most powerful and destructive effects of climate change which makes active participation in the Paris Agreement increasingly important. He expressed his concern that the richest and most powerful countries are backing off, emphasizing the role of these countries as both global leaders and top producers of CO2. He also shared his hopes that the OECD will continue to work to fill the absence of the United States, and stressed the importance of acquiring 10 billion USD by 2020 to fund mitigation and adaptation technologies for developing countries’ CO2 emissions. Click for President Shin's opening remarks
2017.11.29
View 6968
In Jin Cho Earned the Best Poster Prize at ME Summit 2017
In Jin Cho, a Ph.D. student in the Department of Chemical and Biomolecular Engineering at KAIST received the best poster prize at the International Metabolic Engineering Summit 2017 held on October 24 in Beijing, China. The International Metabolic Engineering Summit is a global conference where scientists and corporate researchers in the field of metabolic engineering present their latest research outcomes and build networks. At this year’s summit, about 500 researchers from around the world participated in active academic exchanges, including giving keynote speeches and presenting posters. During the poster session, the summit selects one person for the KeAi-synthetic and Systems Biotechnology Poster Award, two for Microbial Cell Factories Poster Awards, and three for Biotechnology Journal Poster Awards among the posters presented by graduate students, post-doctoral fellows and researchers. Cho received the KeAi-synthetic and Systems Biotechnology Poster Award. Her winning poster is on the biotransformation of p-xylene to terephthalic acid using engineered Escherichia coli. Terephthalic acid is generally produced by p-xylene oxidation; however, this process requires a high temperature and pressure as well as a toxic catalyst during the reaction process. Cho and Ziwei Luo, a Ph.D. student at KAIST, co-conducted the research and developed a successful biological conversion process. Compared to the existing chemical process, it does not require a high temperature and pressure; and it is environmentally friendly with a relatively high conversion rate of approximately 97%. Cho’s advisor, Distinguished Professor Sang Yup Lee said, “Further research on glucose-derived terephthalic acid will enable us to produce biomass-based eco-friendly terephthalic acid through engineered Escherichia coli.”
2017.10.31
View 7398
Professor Nam Jin Cho Selected as the Eugene P. Wigner Reactor Physicist Awardee
Professor Nam Jin Cho from the Department of Nuclear & Quantum Engineering was selected as the recipient of the 2017 ‘Eugene P. Wigner Reactor Physicist Award.’ The award, established in 1990 by the American Nuclear Society, honors individuals who have made outstanding contributions to the advancement of the field of reactor physics. The award is named after the late Eugene P. Wigner, a pioneer who helped nurture the nuclear age to technical maturity with his pioneering leadership in reactor design. Professor Cho was recognized for his outstanding leadership and achievement in the field of nuclear physics, especially with his original research in analytic function expansion nodal methods, coarse-mesh angular dependent rebalance methods, and neutron transport calculations. A fellow of the ANS, Professor Cho is the first awardee from the Asian region. Professor Cho gave all the credit to his colleagues and students at KAIST who have spared no effort while working together for three decades. “I am very grateful for the unique academic ambience which made this challenging work possible as well as the government’s continuing funding at the National Research Laboratory project.
2017.07.12
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Professor Poong Hyun Seong Selected as Fellow of the ANS
Professor Poong Hyun Seong of the Department of Nuclear and Quantum Engineering was selected as a fellow of the American Nuclear Society. The selection was announced at their annual meeting held in San Francisco on June 12, in recognition of Professor Seong's contributions to the field of nuclear instrumentation, control andhuman factors engineering. Founded in 1954, the American Nuclear Society selects scholars who have made outstanding achievements and contributions to the development of the nuclear engineering field each year. Professor Seong's researches in the field of nuclear instrumentation, control and human factors engineering have contributed to the safe operation of nuclear power plants, to the development of systems to maintain nuclear power plants safely in the event of emergency and to the enhancement of effective response capabilities of nuclear power plant operators. His researches significantly contributed to the safety improvement of nuclear power plants and have been recognized worldwide. Professor Seong said, "Korea has emerged as a nuclear powerhouse. I think not only my academic career but our national reputation in the field of nuclear research has been well recognized by our global peers.” Professor Seong has served as president of the Korean Nuclear Society, editor in chief of Nuclear Engineering and Technology, and as a commissioner of the Korean Nuclear Safety Commission. He is currently working as a commissioner of the Korean Atomic Energy Commission.
2017.06.29
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Professor Lee Recognized by the KMS as Best Paper Awardee
Professor Ji Oon Lee of the Department of Mathematical Sciences was selected as the 2017 Best Paper Awardee by the Korean Mathematical Society. The award will be presented during the KMS spring meeting on April 29. Dr. Lee is being honored for proving a necessary and sufficient condition for the Tracy-Wisdom law of Wigner matrices. In a paper titled ‘A Necessary and Sufficient Condition for Edge Universality of Wigner Matrices,’ he proposed a solution for one of the many unanswered problems in the field of random matrix theory that have existed for decades. The paper, co-authored with Professor Jun Yin at the University of Wisconsin – Madison, was published in the Duke Mathematical Journal in 2014. Professor Lee joined KAIST in 2010 after finishing his Ph.D. at Harvard University. He was named a ‘POSCI Science Fellow’ and received the ‘Young Scientist Award’ from the KMS in 2014.
2017.04.27
View 7192
Crowdsourcing-Based Global Indoor Positioning System
Research team of Professor Dong-Soo Han of the School of Computing Intelligent Service Lab at KAIST developed a system for providing global indoor localization using Wi-Fi signals. The technology uses numerous smartphones to collect fingerprints of location data and label them automatically, significantly reducing the cost of constructing an indoor localization system while maintaining high accuracy. The method can be used in any building in the world, provided the floor plan is available and there are Wi-Fi fingerprints to collect. To accurately collect and label the location information of the Wi-Fi fingerprints, the research team analyzed indoor space utilization. This led to technology that classified indoor spaces into places used for stationary tasks (resting spaces) and spaces used to reach said places (transient spaces), and utilized separate algorithms to optimally and automatically collect location labelling data. Years ago, the team implemented a way to automatically label resting space locations from signals collected in various contexts such as homes, shops, and offices via the users’ home or office address information. The latest method allows for the automatic labelling of transient space locations such as hallways, lobbies, and stairs using unsupervised learning, without any additional location information. Testing in KAIST’s N5 building and the 7th floor of N1 building manifested the technology is capable of accuracy up to three or four meters given enough training data. The accuracy level is comparable to technology using manually-labeled location information. Google, Microsoft, and other multinational corporations collected tens of thousands of floor plans for their indoor localization projects. Indoor radio map construction was also attempted by the firms but proved more difficult. As a result, existing indoor localization services were often plagued by inaccuracies. In Korea, COEX, Lotte World Tower, and other landmarks provide comparatively accurate indoor localization, but most buildings suffer from the lack of radio maps, preventing indoor localization services. Professor Han said, “This technology allows the easy deployment of highly accurate indoor localization systems in any building in the world. In the near future, most indoor spaces will be able to provide localization services, just like outdoor spaces.” He further added that smartphone-collected Wi-Fi fingerprints have been unutilized and often discarded, but now they should be treated as invaluable resources, which create a new big data field of Wi-Fi fingerprints. This new indoor navigation technology is likely to be valuable to Google, Apple, or other global firms providing indoor positioning services globally. The technology will also be valuable for helping domestic firms provide positioning services. Professor Han added that “the new global indoor localization system deployment technology will be added to KAILOS, KAIST’s indoor localization system.” KAILOS was released in 2014 as KAIST’s open platform for indoor localization service, allowing anyone in the world to add floor plans to KAILOS, and collect the building’s Wi-Fi fingerprints for a universal indoor localization service. As localization accuracy improves in indoor environments, despite the absence of GPS signals, applications such as location-based SNS, location-based IoT, and location-based O2O are expected to take off, leading to various improvements in convenience and safety. Integrated indoor-outdoor navigation services are also visible on the horizon, fusing vehicular navigation technology with indoor navigation. Professor Han’s research was published in IEEE Transactions on Mobile Computing (TMC) in November in 2016. For more, please visit http://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=7349230http://ieeexplore.ieee.org/document/7805133/
2017.04.06
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Nobel Laureate Dr. John Michael Kosterlitz Speaks at KAIST
KAIST’s Department of Physics will invite one of three co-recipients of the Nobel Prize in Physics 2016, Professor John Michael Kosterlitz of Brown University, on January 9, 2017, to speak about the exotic states of matter, which is entitled “Topological Defects and Phase Transitions.” Professor Kosterlitz shares the Nobel award with two other researchers, David Thouless and Duncan Haldane. He is considered one of the pioneers in the field of topological phases. In the early 1970s, along with Thouless, he demonstrated that superconductivity could occur at low temperatures and explained the mechanism behind, phase transition, that makes superconductivity disappear at higher temperatures. Over the last decade, topological materials and their applications have been widely studied with the hope of using them in new generations of electronics and superconductors, or in future quantum computers. Details of the lecture follow below: Distinguished Lecture Series by KAIST’s Physics Department · Speaker: Professor John Michael Kosterlitz of the Physics Department, Brown University · Topic: “Topological Defects and Phase Transitions” · Date: January 9, 2017, 4:00 PM · Place: Lecture Hall (#1501), College of Natural Sciences (E6-2)
2017.01.06
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Mechanical Engineering Building on Campus Refurbished
KAIST’s Mechanical Engineering Department has finished the project to remodel its buildings and hosted an opening ceremony on December 12, 2016, which was attended by the university’s senior management and guests including President Steve Kang and Choong-Hwan Ahn, Architecture Policy Officer at the Ministry of Land, Infrastructure and Transport of Korea (MLIT). With an investment of approximately USD 10 million, the old buildings (each consisting of seven floors and one basement) were transformed into smart, green buildings. Among the upgrades were the establishment of LED lighting systems, the replacement of the exterior walls with insulated materials, and the installation of double-glazed windows, all resulting in the improvement of the buildings’ energy efficiency. Previously, offices and lecture halls in the buildings had individual cooling and heating systems, which consumed a great deal of energy, but they were replaced with a centralized smart energy control system that monitors the operation status as well as energy consumption in real time. With these new improvements, the Department was able to slash its energy consumption by 32%, for which it received Green Building Conversion Certification from MLIT. The ministry issues the certification to buildings that reduce their energy consumption by over 20% as a result of infrastructure upgrades. Beginning with the Mechanical Engineering buildings, KAIST will work on obtaining this certification for all of its buildings that are either under renovation or construction. President Kang said, “We are pleased to offer our students a comfortable environment for study and research and will continue improving outdated facilities and infrastructure to make the campus safer and nicer.” Picture 1: Ribbon-cutting ceremony for the refurbished Mechanical Engineering buildings on campus Picture 2: Mechanical engineering buildings
2016.12.09
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KAIST Team Develops Semi-Transparent Solar Cells with Thermal Mirror Capability
A research team led by KAIST and Sungkyunkwan University professors has created semi-transparent perovskite solar cells that demonstrate high-power conversion efficiency and transmit visible light while blocking infrared light, making them great candidates for solar windows. Modern architects prefer to build exteriors designed with glass mainly from artistic or cost perspectives. Scientists, however, go one step further and see opportunities from its potential ability to harness solar energy. Researchers have thus explored ways to make solar cells transparent or semi-transparent as a substitute material for glass, but this has proven to be a challenging task because solar cells need to absorb sunlight to generate electricity, and when they are transparent, it reduces their energy efficiency. Typical solar cells today are made of crystalline silicon, but it is difficult to make them translucent. Semi-transparent solar cells under development use, for example, organic or dye-sensitized materials, but compared to crystalline silicon-based cells, their power-conversion efficiencies are relatively low. Perovskites are hybrid organic-inorganic halide-based photovoltaic materials, which are cheap to produce and easy to manufacture. They have recently received much attention as the efficiency of perovskite solar cells has rapidly increased to the level of silicon technologies in the past few years. Using perovskites, a Korean research team led by Professor Seunghyup Yoo of the Electrical Engineering School at KAIST and Professor Nam-Gyu Park of the Chemical Engineering School at Sungkyunkwan University developed a semi-transparent solar cell that is highly efficient and, additionally, functions very effectively as a thermal-mirror. The team has developed a top transparent electrode (TTE) that works well with perovskite solar cells. In most cases, a key to success in realizing semi-transparent solar cells is to find a TTE that is compatible with a given photoactive material system, which is also the case for perovskite solar cells. The proposed TTE is based on a multilayer stack consisting of a metal film sandwiched between a high refractive-index (high-index) layer and an interfacial buffer layer. This TTE, placed as a top-most layer, can be prepared without damaging ingredients used in perovskite solar cells. Unlike conventional transparent electrodes focusing only on transmitting visible light, the proposed TTE plays the dual role of passing through visible light while reflecting infrared rays. The semi-transparent solar cells made with the proposed TTEs exhibited average power conversion efficiency as high as 13.3% with 85.5% infrared rejection. The team believes that if the semi-transparent perovskite solar cells are scaled up for practical applications, they can be used in solar windows for buildings and automobiles, which not only generate electrical energy but also enable the smart heat management for indoor environments, thereby utilizing solar energy more efficiently and effectively. This result was published as a cover article in the July 20, 2016 issue of Advanced Energy Materials. The research paper is entitled “Empowering Semi-transparent Solar Cells with Thermal-mirror Functionality.” (DOI: 10.1002/aenm.201502466) The team designed the transparent electrode (TE) stack in three layers: A thin-film of silver (Ag) is placed in between the bottom interfacial layer of molybdenum trioxide (MoO3) and the top high-index dielectric layer of zinc sulfide (ZnS). Such a tri-layer approach has been known as a means to increase the overall visible-light transmittance of metallic thin films via index matching technique, which is essentially the same technique used for anti-reflection coating of glasses except that the present case involves a metallic layer. Traditionally, when a TE is based on a metal film, such as Ag, the film should be extremely thin, e.g., 7-12 nanometers (nm), to obtain transparency and, accordingly, to transmit visible light. However, the team took a different approach in this research. They made the Ag TE two or three times thicker (12-24 nm) than conventional metal films and, as a result, it reflected more infrared light. The high refractive index of the ZnS layer plays an essential role in keeping the visible light transmittance of the proposed TTE high even with the relatively thick Ag film when its thickness is carefully optimized for maximal destructive interference, leading to low reflectance (and thus high transmittance) within its visible light range. The team confirmed the semi-transparent perovskite solar cell’s thermal-mirror function through an experiment in which a halogen lamp illuminated an object for five minutes through three mediums: a window of bare glass, automotive tinting film, and the proposed semi-transparent perovskite solar cell. An infrared (IR) camera took thermal images of the object as well as that of each window’s surface. The object’s temperature, when exposed through the glass window, rose to 36.8 Celsius degrees whereas both the tinting film and the cell allowed the object to remain below 27 Celsius degrees. The tinting film absorbs light to block solar energy, so the film’s surface became hot as it was continuously exposed to the lamp light, but the proposed semi-transparent solar cell stayed cool since it rejects solar heat energy by reflection, rather than by absorption. The total solar energy rejection (TSER) of the proposed cell was as high as 89.6%. Professor Yoo of KAIST said, “The major contributions of this work are to find transparent electrode technology suitable for translucent perovskite cells and to provide a design approach to fully harness the potential it can further deliver as a heat mirror in addition to its main role as an electrode. The present work can be further fine-tuned to include colored solar cells and to incorporate flexible or rollable form factors, as they will allow for greater design freedom and thus offer more opportunities for them to be integrated into real-world objects and structures such as cars, buildings, and houses.” The lead authors are Hoyeon Kim and Jaewon Ha, both Ph.D. candidates in the School of Electrical Engineering at KAIST, and Hui-Seon Kim, a student in the School of Chemical Engineering at Sungkyunkwan University. This research was supported mainly by the Climate Change Research Hub Program of KAIST. Picture 1: Semi-transparent Perovskite Solar Cell This picture shows a prototype of a semi-transparent perovskite solar cell with thermal-mirror functionality. Picture 2: A Heat Rejection Performance Comparison Experiment This picture presents thermal images taken by an infrared camera for comparing the heat rejection performance of bare glass, automotive tinting film, and a semi-transparent perovskite solar cell after being illuminated by a halogen lamp for five minutes.
2016.08.02
View 11114
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