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- [Alumni] 조형균 교수님 연구실 최지훈 연구원, BK장기해외연수 소감
- [[연수 소감]] 글 : 최지훈 Greetings, I am Jihoon Choi, a graduate student in the 8th semester of the combined master's and doctoral program within the Department of Materials Science and Engineering at Sungkyunkwan University. I had the privilege of serving as a visiting researcher at the University of Pennsylvania (UPenn) in the United States from March 2023 to the end of August 2023, thanks to the BK long-term overseas training program. In this article, I will share my research impressions and insights gained during this enriching experience. Research Focus: My current research revolves around the field of hydrogen production through water splitting using solar energy. During my time at UPenn, I had the opportunity to work alongside Professor Eric A. Stach's group, a renowned electron microscopy research team specializing in the analysis of energy conversion materials. Transmission Electron Microscopy (TEM) Expertise: A key aspect of my training was acquiring expertise in Transmission Electron Microscopy (TEM) and Spherical Aberration Correction Scanning TEM (STEM). TEM analysis plays a pivotal role in materials engineering research, but it is often challenging to access outside specialized laboratories. Through this overseas experience, I spent over 100 hours working directly with TEM, significantly expanding my skill set. Notably, our research focused on in-situ TEM analysis, a technique limited to only a handful of laboratories. We employed a nano-scale 3-electrode chip to facilitate electrolyte flow, enabling us to investigate the growth and stability of nanomaterials through electrochemical reactions within a TEM holder. My work involved capturing images of the nanoparticle catalyst growth process during these electrochemical reactions. Collaborative Efforts: Collaboration was a cornerstone of my overseas experience. I partnered with a postdoctoral researcher from a fellow overseas laboratory within our organization. Together, we undertook a study aimed at achieving a highly uniform distribution of molecular catalysts at the single-atom level on a silicon substrate. Subsequently, we applied machine learning techniques to post-process TEM images, a cutting-edge approach actively explored within recent academic circles, to ascertain the distribution and size of single-atom catalysts. My time at UPenn was invaluable in broadening my scientific horizons. I actively participated in cutting-edge research, leveraged state-of-the-art scientific equipment, attended meetings at renowned university laboratories, and delivered presentations, all of which contributed significantly to my academic and professional growth.
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- 작성일 2023-09-07
- 조회수 1978
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- [Research] Prof. Sunkook Kim's Develops Nanoporus IGZO Applicable to Visible-to-NIR detecting photo transistor
- Prof. Sunkook Kim's (Department of Advanced Materials Science and Engineering) Develops Nanoporus IGZO Applicable to Visible-to-NIR detecting photo transistor Professor Sunkook Kim’s research team (Department of Advanced Materials Science and Engineering) proposed an approach for detecting wide spectral range using indium gallium zinc oxide (IGZO) phototransistors. IGZO phototransistors have limited applicability in broad spectral range detection; to solve this many research had been done using external photo-absorber. Our team developed nanoporous IGZO phototransistors, which can detect near infrared (NIR) without using any absorber. IGZO is optically transparent due to a bandgap of nearly 3–4 eV; thus, to extend the light detection range of IGZO, a laminated approach that introduces secondary materials has been suggested in previous reports. An additional optical absorption layer with a narrower bandgap on the IGZO thin film has been investigated in various studies. These absorption layers include CdSe, CdS, and PbS quantum dots; graphene dots; metal nanoparticles; and films of selenium. Heterojunctions of two-dimensional MoS2, graphene, and perovskite (CsPblxBr3-x) with IGZO films have also been investigated. To solve this problem, Sunkook Kim’s research team investigated the performance of nanoporous IGZO phototransistors. The nanopores throughout the entire thickness of ~ 30 nm in (IGZO) created by block co-polymer lithography. The process of creating a nonporous morphology is sophisticated and is accessed using a wafer-scale phototransistor array. See-through nanopores have edge functionalization with vacancies, which leads to a large subgap states within the conduction band minima and valence band maxima. These subgap states further contribute to detect NIR by employing photogating effect. The performance of the phototransistors is assessed in terms of photosensitivity (S) and photoresponsivity (R); both are of high magnitudes (S = 8.6×104 at ex = 638 nm and Pinc = 512 mW cm⁻2; R = 120 A W⁻1 at Pinc = 2 mW cm⁻2 for the same ex). Additionally, the 7 × 5 array of 35 phototransistors is effective in sensing and reproducing the input image by responding to selectively illuminated pixels. Prof. Kim said, “This study is significant for developing IGZO phototransistors for visible -NIR detection without using photo-absorber”. This study was supported by the SKKU Research Fellowship Program of Sungkyunkwan University and in part by the Basic Science Research Program through the National Research Foundation of Korea (NRF-2021R1A2B5B02002167, 2021M3H4A1A02056037, 2021R1I1A1A01060065, and 2021R1I1A1A01060078) and published on 13th June 2022 in ACS Nano (I.F:18.03) Paper name: Probing the Efficacy of Large-Scale Nonporous IGZO for Visible-to-NIR Detection Capability: An Approach toward High-Performance Image Sensor Circuitry DOI: https://doi.org/10.1021/acsnano.2c01773 Article by Sen Anamika
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- 작성일 2022-11-16
- 조회수 6079
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- [Research] Prof. Sunkook Kim develops large area MoS2 film for transparent phototransistor
- Prof. Sunkook Kim ((Department of Advanced Materials Science and Engineering) develops large area MoS2 film for transparent phototransistor by plasma assisted chemical vapor deposition technique. Professor Sunkook Kim’s research team (Department of Advanced Materials Science and Engineering) developed a route to synthesis low temperature plasma assisted large area MoS2 film for transparent phototransistor. Transparent devices on low-cost glass substrate using transition metal dichalcogenides (TMDs), required additional mechanical transfer which induces wrinkles, voids, cracks on the channel and hinder the mass production. TMDs such as MoS2 have attracted considerable attention or the fabrication of ultra-sensitive and ultrathin photodetectors because of their layer-dependent bandgap, optical transparency, high current on/off ratio, high carrier mobility, temperature stability, and large scalability. However, the synthesis of MoS2 required high temperature (> 600 °C), therefore growth on an inexpensive transparent substrate with low thermal budgets is challenging. Numerous techniques have been proposed for obtaining MoS2 at low temperature (< 400 °C) including MOCVD, ALD, PECVD etc. MOCVD required long sulfurization time for large area coverage, while ALD either required post annealing or produce rough film at low temperature. Few groups have used PECVD to grow large area MoS2 film at low temperature, however poor quality of the film hinder their application in transistor. Research team of Professor Sunkook Kim (Arindam Bala, Liu Na and all the authors) have synthesis large area MoS2 film on inexpensive slide glass (MARIENFELD.) by plasma assisted chemical vapor deposition technique (≤ 400 °C) and fabricated 7 × 7 array of transparent phototransistor without additional mechanical transfer, which can detect visible light (λ = 405 nm, 652 nm). Prof. Kim said, “This study is significant for developing low-cost smart glass technologies”. This research was supported in part by the National Research Foundation of Korea. (No. 2021R1A2B5B02002167, 2020H1D3A2A02103378, 2020R1I1A1A01052893) This work was supported by Institute of Information & communications Technology Planning & Evaluation (IITP) grant funded by the Korea government (MSIT) (No. 2021-0-01151) and published on 10th August 2022 in Advanced Functional Materials (I.F.: 19.92). Paper name: Low-Temperature Plasma-Assisted Growth of Large-Area MoS2 for Transparent Phototransistors. DOI: https://doi.org/10.1002/adfm.202205106 Article by Bala Arindam
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- 작성일 2022-11-16
- 조회수 3901
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- [Research] J.-Y. Choi / H. K. Yu joint research team develops Ultrahigh Porosity MgO Microparticles for Heat-Energy storage
- J.-Y. Choi / H. K. Yu joint research team develops Ultrahigh Porosity MgO Microparticles for Heat-Energy storage The joint research team led by Professor Jae-Young Choi at SKKU school of advanced materials science, and engineering and professor Hak Ki Yu at Ajou University department of materials science and engineering has developed Ultrahigh-Porosity MgO Microparticles for thermochemical heat-storage reaction with high stability and exceptional reactant permeability. Professor Choi is also the co-CEO of C&C materials. Regarding paper has been published on Advanced Materials with the title “Ultrahigh-Porosity MgO Microparticles for Heat-Energy Storage”. Research on renewable energy, and waste heat retrieval and conversion, has been the key for carbon neutrality. Among those research retrieval of industrial waste heat has earned significant interest. Naturally, the development of materials that can meet the criteria for industrial waste heat retrieval is now more important than ever. Fig. Schematic illustration of the strategy for synthesizing porous MgO and images of a porous MgO particle. The research team has introduced ultrahigh porous structure to magnesium oxide (MgO), a highly promising candidate for waste heat storage, to develop high-performance heat energy storing material. This Ultrahigh Porosity MgO has 4 times more surface area than commercial MgO, and therefore is free of swelling during heat storage, enabling heat storage capacity 7.2 times bigger than commercial MgO. This Ultra-high Porosity MgO is expected to serve as key material for chemically storing industrial waste heat, and the research team will carry out follow-up research to develop new materials and control the structure of existing materials to overcome obstacles of nanomaterials. Funded by the National Research Foundation of Korea (NRF), this work has been published on Advanced Materials (IF=32.086) in July 2022. ※ Title: Ultrahigh-Porosity MgO Microparticles for Heat-Energy Storage ※ Authors: Youngho Kim1, Xue Dong1, Sudong Chae1, Ghulam Asghar, Sungwoong Choi, Bum Jun Kim#, Jae-Young Choi#, Hak Ki Yu# ※ DOI: https://doi.org/10.1002/adma.202204775 1 : Lead author 2 : Corresponding author
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- 작성일 2022-09-19
- 조회수 3934
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- [Research] Artificial intelligence (AI) for understanding and characterizing the ductile-brittle behaviors of Mg based materials
- Artificial intelligence (AI) for understanding and characterizing the ductile-brittle behaviors of Mg based materials On June11th, the research team led by Prof. Kotiba Hamad at the school of advanced materials science and engineering (AMSE)published a paper titled “Brittle and ductile characteristics of intermetallic compounds in magnesium alloys : A large-scale screening guided by machine learning” in the Journal of Magnesium and Alloys (IF =11.8) which is ranked the 1st in the category of metallurgy & metallurgical engineering according to Clarivate’s Journal Citation Reports’ (JCR) ranking. This study is one of the woks conducted by this group to investigate the applicability and the potential of AI techniques in the field of materials discovery and design. The findings of this work showed that, by machine learning (ML), a technique of AI, the brittle-ductile characteristics of intermetallic compounds that form in magnesium-based alloys are reliably, accurately, and quickly predicted. The ML results were validated by theoretical calculations done by density functional theory (DFT), shown by the figure below. The results can facilitate the designing of magnesium alloys with high performance for structural applications. This led to say that, due to the exploding computational capabilities, artificial intelligence, in its machine learning subcategory, has been utilized heavily in the field of material discovery and design for its ability to construct data-driven models that are magnitude faster than conventional experimentation or even physics-driven modeling and simulation. The present research group; Kotiba Hamad (Professor), Russlan Jaafreh (PhD candidate), Kang Woo Seong (Graduate collaborator/Currently working in ‘Computer Systems and Intelligence Laboratory’), and Santiago Pereznieto (Masters Student), have been utilizing the capabilities of AI in the field of material science & engineering, and have published multiple papers regarding this topic in high-tier journals such as: ACS Applied Materials & Interfaces, Journal of Materiomics and many more. Related Links and professor’s website: - Russlan Jaafreh, Yoo Seong Kang, Kotiba Hamad, Journal of Magnesium and Alloys 2022, DOI: doi.org/10.1016/j.jma.2022.05.006. - Russlan Jaafreh, Yoo Seong Kang, and Kotiba Hamad, ACS Applied Materials & Interfaces 2021 13 (48), 57204-57213, DOI: doi.org/10.1021/acsami.1c17378 - Professor Kotiba’s Website: kotibahamad995.wixsite.com/aem-skku
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- 작성일 2022-08-16
- 조회수 3902
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- [Research] Prof. Yunseok Kim’s research team demonstrates a new strategy for highly enhanced ferroelectricty
- Prof. Yunseok Kim’s research team demonstrates a new strategy for highly enhanced ferroelectricty in HfO2-based ferroelectrics using ion bombardment - Published in ‘Science’ - These findings open pathways for nanoengineered binary ferroelectrics and subsequent ferroelectric-seminconductor integration. The research team* of Professor Yunseok Kim demonstrate a way to highly enhance ferroelecticity of HfO2-based ferroelectrics using ion bombardment. * Co-corresponding authors : Prof. Young-Min Kim(SKKU), Dr. Jinseung Heo (Samsung Advanced Institute of Technology), Dr. Sergei Kalinin (Oak Ridge National Laboratory, USA) Continuous advancement in nonvolatile and morphotropic beyond-Moore electronic devices necessitates the development of strategies that utilize the wealth of functionalities of complex materials at extremely reduced dimensions. The discovery of ferroelectricity in hafnium oxide (HfO2)–based ferroelectrics that are compatible with the semiconductor process has opened interesting and promising avenues of research. However, the origins of ferroelectricity and pathways to controlling it in HfO2-based ferroelectrics are still mysterious. We report that local ion bombardment can activate ferroelectricity in these materials. The possible competing mechanisms, including ion–induced molar volume changes, vacancy redistribution, vacancy generation, and activation of vacancy mobility, are discussed. These findings including the variation of ferroelectricity through defect engineering based on ion bombardment suggest additional possibilities for ferroelectricity enhancement in HfO2-based ferroelectrics. Furthermore, this approach can be directly applied to a semiconductor process without structural modification and, thus, can increase its applicability in next-generation electronic devices, such as ultrascaled ferroelectrics-based transistors and memories. Paper ○ “Highly enhanced ferroelectricity in HfO2-based ferroelectric thin film by light ion bombardment”, Science 376(6594), 731-738 (2022) ○ URL: https://www.science.org/doi/10.1126/science.abk3195 Webpage: http://spm.skku.edu
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- 작성일 2022-07-27
- 조회수 3432
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- [Research] Prof. Jeong Min Baik’s research group develops high-performing SCR catalysts for tackling air pollution
- Prof. Jeong Min Baik’s research group develops high-performing SCR catalysts for tackling air pollution - Low-temperature SCR catalyst developed impregnating highly-dispersed CuO–CeO2 nano-heterostructures - Published in Chemical Engineering Journal on Feb, 2022 Prof. Jeong Min Baik’s research group in tandem with Dr. Hong-Dae Kim (KITECH) and Prof. Hyesung Park (UNIST) developed nitrogen oxides (NOx) removal catalyst exhibiting superior catalytic performance at the low temperature (180oC~220oC). Selective Catalytic Reduction (SCR), is a widely-used industrial technique that converses the NOx—the leading cause of the air pollution—into N2 or H2O by using ammonia as a reducing agent. However, widely-used VO2/TiO2 catalysts have fatal setbacks such as causing catalytic deactivation owing to agglomeration with its limited performance at high operation temperature (250℃ or higher), not to mention its high maintenance costs. Therefore, developing a low-temperature catalyst showing high activation at about 200℃ increasingly gained importance, though, deactivation owing to SO2 and water used to be a challenge. To cope with, the research team fabricated ultra-small (<5 nm in size) CuO–CeO2 heterostructures with atomically well-defined interface followed by impregnation to V2O5–WO3-CeO2/TiO2 (2V-10Ce-1W/Ti) catalysts, achieving 44% higher Nox removal efficiency than the conventional catalysts. Also, they succeeded in raising K-factor (K16h/K0) from 0.60 to 0.83 under SO2 atmosphere, as well as the resistance towards the water. “We are soon going to check its industrial applicability through conducting empirical experiments. Through follow-up research, we will develop catalysts with a longer operation at below 200°C." Prof. Baik stated. In this regard, the research team has already applied for two patents. The experts expect that the cost for reducing NOx emissions from industrial sites such as factories and steel mills will be drastically reduced. This work was supported by the Ministry of Trade, Industry, and Energy, South Korea (MOTIE, 20005721), by the Mid-Career Researcher Program through the National Research Foundation of Korea (NRF) grant funded by the Korea government (NRF-2019R1A2C2009822), and by National R&D Program through the National Research Foundation of Korea(NRF) funded by Ministry of Science and ICT (2021M3C1C309). ※ Paper : Cu- and Ce- promoted nano-heterostructures on vanadate catalysts for low-temperature NH3-SCR activity with improved SO2 and water resistance ※ https://doi.org/10.1016/j.cej.2022.135427
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- 작성일 2022-04-22
- 조회수 3632
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- [Faculty] Professor Jung selected as SKKU Fellowship Professor
- 2021 SKKU-Fellowship Professor Sungkyunkwan University selected the ‘2021 SKKU-Fellowship’ professors. The list of professors starts with D. Normandin Shawn (English Language and Literature), Doo Jin Ryu (Economics), Hoon Seok Choi (Phychology), Donghun Lee (Education), Jae Seong Lee (Biological Sciences), Junsin Yi (Electronic and Electrical Engineering), Jun Yeob Lee (Chemical Engineering), Hyun Suk Jung (Advanced Materials Sciences and Engineering), Sang Won Seo (Medicine), Seung Ho Ryu (Medicine), Yoon Suk Jung (Medicine). The SKKU-Fellowship system has been awarded by Sungkyunkwan University since 2004 and is a system that grants exceptional research support and honor by selecting the best professor whose level of research capability has settled on global standards. The purpose of this scheme is to improve the research environment, which allows professors with the highest level of research to demonstrate world-class research capabilities more qualitatively than quantitative growth by minimizing lecturing duties.
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- 작성일 2022-02-23
- 조회수 3143
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- [Alumni] Dr. Seong in Hong employed as an assistant professor at Gachon University
- Dr. Seong in Hong employed as an assistant professor at Gachon University Dr. Seong in Hong from Nano/Bio AI Electronics Lab (NBAIEL) is starting his career as an assistant professor at the department of physics, Gachon University in coming March. Dr. Hong was honored Ph.D. degree with his study, “Thin film field-effect phototransistors” and served as a postdoctoral researcher at the University of Texas at Austin. Dr. Hong, under Prof. Sunkook Kim’s guidance, is highly engaged in developing next-generation semiconductor materials. His findings were published in a total of 28 distinguished SCI journals such as Nature Communications, Advanced Materials, and ACS Nano. Moreover, while he was a Ph.D. candidate, he was selected for national research projects such as [NRF] ROK-CANADA Global Research Program (GRA), [NRF] Creative-challenge Research Project, [BK] Global Postdoctoral Fellowship Program (GPF). Dr. Hong also had a few challenges to this end, due to lab relocation, pandemic-related research frustration, and so on. However, with support and encouragement from the advisor, Prof. Sunkook Kim, he has managed difficult situations into opportunities. According to Dr. Hong, transfer to AMSE broaden his horizons as a researcher and drove his resolution to remain in the field to extend his research and foster experts. Dr. Hong managed this pandemic crisis by devoting his time to innovative studies as a post-doctor in Prof. Kim’s lab. He said, “As a result, I was able to expand my research capability during my time at AMSE, with its superior research infrastructure and support.” Currently, Dr. Hong is leading ‘Overwhelming Nano Electronics Laboratory’ after being appointed at Gachon University. He is committed to grow cutting-edge semiconductor materials to develop devices with top-notch performance.
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- 작성일 2022-02-15
- 조회수 2265
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- [Research] Prof. Sang-woo Kim’s research team develops world’s first ultrasound-mediated Fully Biodegradable and Implantable Triboe
- Prof. Sang-Woo Kim’s research team develops world’s first ultrasound-mediated Fully Biodegradable and Implantable Triboelectric Nanogenerator - Promising solution for eliminating the need for secondary surgery to remove the implantable medical devices (IMD) after the clinical timelines [Image] Prof. Sang-Woo Kim, Ph.D. Candidate Dong-Min Lee, and Najaf Rubab (from the left) The research team led by Prof. Sang-Woo Kim developed the world’s first ultrasound-mediated Fully Biodegradable and Implantable Triboelectric Nanogenerator (FBI-TENG). By mediating the ultrasound intensity, the FBI-TENG can be fully dissolved in the body in a short period of time at any specific moment with eliminating the need for secondary surgery to remove IMDs. Implantable electroceuticals, a class of technology that cures diseases (e.g., pain, and depression) in a short time (generally within 6 months), are of great interest in areas throughout medicine, and biomedical implants. However, they require the secondary surgery to remove the implants, which causes physical and psychological burden to patients. Many researches have been reported to develop implantable electroceuticals that equip biodegradable functions, but they encountered critical challenge, full biodegradation in a controlled manner within several minutes. Conventional transient materials were limited to exploit passive degradation, relying on their own thickness and material properties. In addition, they require at least several weeks to months for themselves to be fully degraded inside the body, which their residues can induce severe toxicity or negative health conditions. [Figure 1] Schematic of an Ultrasound-mediated in vivo biodegradable triboelectric nanogenerator Herein, the research team suggested a promising solution for minimizing the potential negative factors to health conditions, by developing the technology that dissolve the device within 30 minutes in a controlled manner using medically available ultrasound. [Figure 2] Theoretical and experimental studies of transient performances for FBI-TENG under ultrasound stimulation. The research team demonstrated that the FBI-TENG generates electricity without power degradation under the low-intensity ultrasound (1.0 W cm-2) and performs transient processes at the programmed time under high-intensity ultrasound (3.0 W cm-2). [Figure 3] Ex vivo demonstration of ultrasound triggered biodegradation FBI-TENG. The research team inserted the FBI-TENG into porcine tissue, a comparable anatomical structure to human, to conduct ex-vivo experiments. They found that the high-intensity ultrasound (3.0 W cm-2) can dissolve the device within few minutes inside the tissue. [Figure 4] Evaluation of Energy Generation of FBI-TENG The research team confirmed stable power generation (0.34 V and 3.20 μA) and complete biodegradation of the FBI-TENG, inserted at the 0.5 cm depth from the porcine epidermis, in 40 minutes by mediating ultrasound intensity. Prof. Sang-Woo Kim said, “it is an outstanding development that the FBI-TENG is the world’s first biodegradable and implantable TENG that can be fully biodegraded in a short time just by mediating the ultrasound intensity”. He added, “we expect the findings can be a promising approach for the next-generation medical device industries.” This work was financially supported by Nano Material Technology Development Program (2020M3H4A1A03084600) and Basic Science Research Program (2021R1A2C2010990) through the National Research Foundation (NRF) of Korea grant. This research was published in Science Advances on January 7, an international academic journal published by the American Association for Advancement of Science (AAAS) Paper: Ultrasound-mediated triboelectric nanogenerator for powering on-demand transient electronics
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- 작성일 2022-02-03
- 조회수 3095