Article
Chemistry, Multidisciplinary
Felipe Crasto de Lima, Adalberto Fazzio
Summary: Vacancies play a crucial role in the topological transition of transition metal dichalcogenides, inducing a topologically nontrivial phase. Vacancy states in PtSe2 result in a large topological gap within the pristine system gap, allowing the construction of backscattering protected metallic channels embedded in a semiconducting host.
Article
Chemistry, Multidisciplinary
Jun Ge, Tianchuang Luo, Zuzhang Lin, Jianping Shi, Yanzhao Liu, Pinyuan Wang, Yanfeng Zhang, Wenhui Duan, Jian Wang
Summary: This study reports the discovery of localized magnetic moments induced by Pt vacancies in PtSe2 flakes, leading to the generation of the Kondo effect, as evidenced by a logarithmic increase in resistance with decreasing temperature and isotropic negative longitudinal magnetoresistance.
ADVANCED MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Mingjie Pu, Wanlin Guo, Yufeng Guo
Summary: Using a combination of non-noble metal atoms and defect-engineered transition metal dichalcogenide (TMD) monolayers, new types of single-atom catalysts for electrochemical CO2RR can be designed, exhibiting better catalytic performance and selectivity. Applying suitable biaxial tensile strains on defect-engineered TMDs can significantly reduce the overpotentials of non-noble metal atoms, with the vacancy defects and charge transfer playing a crucial role in improving catalytic activity.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Multidisciplinary
Wei Wang, Leighton O. Jones, Jia-Shiang Chen, George C. Schatz, Xuedan Ma
Summary: Researchers have successfully achieved single-photon emission by generating defects through UV light in vacuum, while defects created in air do not possess this characteristic. They attribute the defects generated in vacuum to unpassivated sulfur vacancies, which have highly localized midgap states that give rise to single-photon emission.
Article
Chemistry, Multidisciplinary
Xuejing Wang, Michael Thompson Pettes, Yongqiang Wang, Jian-Xin Zhu, Rohan Dhall, Chengyu Song, Andrew C. Jones, Jim Ciston, Jinkyoung Yoo
Summary: Defect engineering with proton irradiation was used to enhance the exciton-to-trion conversion of atomically thin WS2. Scanning transmission electron microscopy, photoluminescence, and Raman spectroscopy confirmed the correlation between altered excitonic states and nanopore-induced atomic displacement, W nanoclusters, and zigzag edge terminations. Density functional theory calculation and ion energy loss simulation provided further evidence for band perturbations and nanopore formation without destroying the overall crystallinity. This study offers a new approach for tuning excitonic properties of van der Waals semiconductors using an irradiation-based defect engineering method.
Article
Chemistry, Multidisciplinary
Anna Zhuravlova, Antonio Gaetano Ricciardulli, Dawid Pakulski, Adam Gorczynski, Adam Kelly, Jonathan N. Coleman, Artur Ciesielski, Paolo Samori
Summary: Chemical sensing of water contamination by heavy metal ions is a severe environmental problem. Two-dimensional transition metal dichalcogenides (TMDs) show potential as chemical sensors due to their high surface-to-volume ratio and unique electrical characteristics, but lack selectivity. In this study, defect-rich MoS2 flakes were functionalized to develop ultrasensitive and selective sensors for cobalt(II) ions. Through a tailored microfluidic approach, a continuous network was formed by healing the sulfur vacancies in MoS2, enabling high control over the assembly of thin and large hybrid films. The developed sensor exhibited a low limit of detection, broad concentration range, and high selectivity towards Co2+ ions.
Article
Chemistry, Physical
Ying Zhao, Yiqing Chen, Pengfei Ou, Jun Song
Summary: This study investigates the role of grain boundaries in polycrystalline MoS2 in the electrocatalytic performance of CO2RR. The introduction of grain boundaries with vacancies is shown to lower the reaction energy and break the scaling relations between reaction intermediates, leading to improved catalytic efficiencies.
Article
Multidisciplinary Sciences
Yoon Seok Kim, Sojung Kang, Jae-Pil So, Jong Chan Kim, Kangwon Kim, Seunghoon Yang, Yeonjoon Jung, Yongjun Shin, Seongwon Lee, Donghun Lee, Jin-Woo Park, Hyeonsik Cheong, Hu Young Jeong, Hong-Gyu Park, Gwan-Hyoung Lee, Chul-Ho Lee
Summary: In this study, atomic-layer-confined multiple QWs were successfully fabricated through monolithic bandgap engineering of transition metal dichalcogenides and van der Waals stacking, leading to superlinear enhancement of photoluminescence and a large exciton binding energy. This work demonstrates the potential of monolithic integration of band-engineered hetero-structures for 2D quantum optoelectronics.
Article
Nanoscience & Nanotechnology
Jeong-Hun Choi, Min-Ji Ha, Dong Geun Kim, Ji-Min Lee, Ji-Hoon Ahn
Summary: This study presented a plasma-enhanced atomic layer deposition (PEALD) process using a new cyclopentadienyl-based Mo precursor (IM-02) to synthesize crystalline MoS2 thin films at a low growth temperature. The resulting MoS2 thin films showed good uniformity and crystallinity, and their quality was further improved by exposure to H2S plasma. These high-quality MoS2 thin films exhibited high selectivity for NO2 gas, indicating their potential for gas sensing applications.
ACS APPLIED NANO MATERIALS
(2023)
Review
Chemistry, Physical
Mengfan Zhou, Wenhui Wang, Junpeng Lu, Zhenhua Ni
Summary: This article summarizes and discusses the influence of defects on PL emission in recent research, focusing on fundamental mechanisms such as radiative/nonradiative recombination kinetics and band structure modification. There are challenges and opportunities in the field of defect manipulation, and exploring mechanisms is expected to promote the future applications of 2D TMDCs.
Article
Energy & Fuels
Sonam Rani, Manushree Tanwar, Meenu Sharma, Love Bansal, Rajesh Kumar, Ravi Bhatia, Sameera Ivaturi
Summary: Among transition metal dichalcogenides, molybdenum disulfide (MoS2) is considered as the most cost-effective electrode material for energy storage applications. Altering the synthesis conditions of MoS2 nanoflowers can result in enhanced charge storage performance.
JOURNAL OF ENERGY STORAGE
(2023)
Review
Chemistry, Physical
Hang Su, Xiaodong Pan, Suqin Li, Hao Zhang, Ruqiang Zou
Summary: In this article, the great potential of two-dimensional transition metal dichalcogenides (TMDs) as cost-effective catalysts in hydrogen evolution reaction is demonstrated. Various defect engineering strategies, including intrinsic defects (vacancy and edges) and extrinsic defects (metal doping, nonmetal doping, and hybrid doping), are systematically summarized. The electronic structure, intermediate adsorption/desorption energies, and possible catalytic mechanisms are discussed based on theoretical simulations and experimental results. The intrinsic relationship between different defect types and electrocatalytic properties is emphasized. Furthermore, current opportunities and challenges for mechanical investigations and applications of defective TMD-based catalysts are presented to provide valuable insights for fabricating high-efficiency TMD-based electrocatalysts.
Article
Chemistry, Multidisciplinary
Inseong Lee, Mingu Kang, Seohak Park, Cheolmin Park, Hyeonji Lee, Sanggeun Bae, Hyeongjin Lim, Sungkyu Kim, Woonggi Hong, Sung-Yool Choi
Summary: This study proposes a method to heal donor defect states in monolayer MoS2 using oxygen plasma, with an aluminum oxide (Al2O3) barrier layer that protects the MoS2 channel from damage. The successful healing of donor defect states in MoS2 by oxygen atoms, even in the presence of an Al2O3 barrier layer, has been confirmed. The proposed method enhances the channel properties of MoS2.
Article
Multidisciplinary Sciences
Viacheslav Sorkin, Hangbo Zhou, Zhi Gen Yu, Kah-Wee Ang, Yong-Wei Zhang
Summary: In this study, the effects of different types, locations, and densities of point defects in monolayer MoS2 on the electronic structures and Schottky barrier heights (SBH) of Au/MoS2 heterojunction are investigated using DFT calculations. The results show that the SBH of monolayer MoS2 with defects is universally higher than that of the defect-free counterpart. Specifically, S divacancy and Mo-S antisite defects have a larger effect on increasing the SBH compared to S monovacancy. Defects located in the inner sublayer of MoS2 also have a larger impact on the SBH than those in the outer sublayer. Increasing defect density leads to a higher SBH. These findings provide practical guidelines for controlling and optimizing the SBH in Au/MoS2 heterojunctions through defect engineering.
SCIENTIFIC REPORTS
(2022)
Article
Chemistry, Multidisciplinary
Kazunori Fujisawa, Bruno R. Carvalho, Tianyi Zhang, Nestor Perea-Lopez, Zhong Lin, Victor Carozo, Sergio L. L. M. Ramos, Ethan Kahn, Adam Bolotsky, He Liu, Ana Laura Elias, Mauricio Terrones
Summary: This study examines defects introduced by controlled irradiation of gallium ions on monolayer molybdenum disulfide crystals, revealing atomic-scale details through Raman spectroscopy and HR-STEM. The research proposes formulas for estimating crystal length and demonstrates the healing of atomic vacancies with annealing in a hydrogen disulfide atmosphere.
Article
Chemistry, Multidisciplinary
Hanbyeol Jang, Yongwook Seok, YiTaek Choi, Sang-Hoo Cho, Kenji Watanabe, Takashi Taniguchi, Kayoung Lee
Summary: The study demonstrates that surface doping with AuCl3 can enhance the performance of InSe photodetectors, surpassing previously reported 2D material-based infrared photodetectors. Investigation of InSe photodetectors with different structures provides insights into the photodetection mechanism and performance optimization. Additionally, encapsulation with hexagonal boron nitride dielectric enables long-term stability of the devices for up to 3 months.
ADVANCED FUNCTIONAL MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Charlie Greboval, Audrey Chu, Debora Vale Magalhaes, Julien Ramade, Junling Qu, Prachi Rastogi, Adrien Khalili, Sang-Soo Chee, Herve Aubin, Gregory Vincent, Sara Bals, Christophe Delerue, Emmanuel Lhuillier
Summary: This paper discusses how field-effect transistors (FETs) can be compatible with low-temperature detection and proposes two key developments. By gating nanocrystal films from SrTiO3 and compatibility with a plasmonic resonator, high gate capacitance and broadband absorption are achieved.
Article
Chemistry, Physical
Ashkan Shahmanesh, Davide Romanin, Corentin Dabard, Sang-Soo Chee, Charlie Greboval, Christophe Methivier, Mathieu G. Silly, Julien Chaste, Matthieu Bugnet, Debora Pierucci, Abdelkarim Ouerghi, Matteo Calandra, Emmanuel Lhuillier, Benoit Mahler
Summary: Researchers explored the colloidal growth of monolayers of WSSe alloy in their 1T' phase with reduced flake aggregation. They found that the electronic structure was weakly affected by alloy content and atomic ordering, with confirmation of the 1T' phase using μ-Raman spectroscopy and STEM. Simulations suggested contributions from both S and Se atoms in the Raman spectra, and electronic transport revealed a short coherence length in the defective flakes.
JOURNAL OF PHYSICAL CHEMISTRY C
(2021)
Article
Chemistry, Multidisciplinary
Hanbyeol Jang, Yumin Song, Yongwook Seok, Heungsoon Im, Tae Hyung Kim, Joo-Hyoung Lee, Yong-Hoon Kim, Kayoung Lee
Summary: This paper presents state-of-the-art self-powered near-infrared sensors utilizing graphene/In/InSe/Au as a photoactive region, exhibiting outstanding performance. Multiple self-powered InSe photodetectors with different device structures and contacts were systematically investigated, with the asymmetrically assembled graphene/In/InSe/Au vertical heterostructure showing efficient electron-hole pair separation. The study also demonstrates InSe vertical field-effect transistors and estimates built-in field, drift velocity, and corresponding transit time using out-of-plane carrier mobility and structural parameters.
Article
Engineering, Chemical
Jaewon Jang, Yesol Kang, Kihyeun Kim, Suhun Kim, Myungwoo Son, Sang-Soo Chee, In S. Kim
Summary: In the face of limitations in previous renewable energy systems, salinity gradient power (SGP) can be a new alternative that is not affected by climate and time. This study proposes a cation exchange membrane (CEM) with engineering nanostructure and introduces a new material for the reverse electrodialysis (RED) system. The Nafion@MXene/Cellulose acetate (CA) composite CEM shows superior physical/electrochemical properties and higher power density in the RED system than other membranes.
JOURNAL OF MEMBRANE SCIENCE
(2022)
Article
Chemistry, Multidisciplinary
Wonsik Kim, Won-June Lee, Taehyun Kwak, Seokhyeon Baek, Seung-Hoon Lee, Sungjun Park
Summary: This study reports a novel method to rapidly reduce threshold voltage using ultraviolet ozone treatment of IGZO layer, which decreases oxygen vacancies and increases bonding, resulting in stable operation and long-term durability of transistors. Depletion-mode inverters fabricated on the same substrate exhibit high gain and moderate noise margin.
ADVANCED MATERIALS INTERFACES
(2022)
Article
Physics, Applied
Jun-Gyu Choi, Won-June Lee, Yong-Ryun Jo, Hyeonjun Na, Sangwoo Lee, Bong-Joong Kim, Myung-Han Yoon
Summary: This study presents a simple method for low-temperature crystallization of solution-processed indium oxide thin films. By introducing ammonium nitrate as a photoactivable additive and applying deep ultraviolet irradiation, the film crystallinity and electrical properties were significantly improved.
APPLIED PHYSICS LETTERS
(2022)
Article
Materials Science, Multidisciplinary
Yeongsik Hwa, Boeun Seok, Sang-Soo Chee
Summary: In this study, different morphologies of tin diselenide were synthesized by a hydrothermal route, and their correlation with NO2 gas detection properties was investigated. The hierarchical morphology of tin diselenide exhibited the best gas detection performance for NO2 at room temperature, attributed to its higher specific surface area and improved crystallinity.
ELECTRONIC MATERIALS LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yeongsik Hwa, Boeun Seok, Jaeha Noh, Sang-Soo Chee
Summary: This study demonstrates the importance of AuCl3 molecular doping for achieving p-type doping effect in BP devices. The doping of AuCl3 on BP leads to a clear transition from ambipolar to unipolar behavior. Additionally, the fabricated 2D diode devices exhibit enhanced rectification and responsivity performance.
ELECTRONIC MATERIALS LETTERS
(2023)
Article
Chemistry, Analytical
Yeongsik Hwa, Sang-Soo Chee
Summary: This study improves the performance of optoelectronic devices by inserting a graphene interlayer between MoS2 films and gold contacts. By using graphene/gold contacts, outstanding electrical properties and responsivity are achieved. These findings are of great significance for constructing large-area photonic sensor arrays.
Article
Materials Science, Multidisciplinary
Taehyun Kwak, Myung-Jin Kim, Won-June Lee, Eun Chae Kim, Jingon Jang, Gunuk Wang, Tae-Wook Kim, Yong Seok Kim, Sungjun Park
Summary: In this study, high-performance and all-solution-processed synaptic transistors were fabricated using a thiol-ene photoclick chemistry-based dielectric layer and sol-gel-derived semiconducting channel layer. The experimental results showed that the fabricated synaptic transistors exhibited remarkable synaptic functionality with high conductance, large dynamic range, and long-term operational stability. This all-solution-derived synaptic transistor can be used as the basis for novel neuromorphic computing systems that require strong neuronal signal transmission and distinguishable multi-level data states.
APPLIED MATERIALS TODAY
(2022)
Review
Chemistry, Analytical
Chuljin Hwang, Won-June Lee, Su Dong Kim, Sungjun Park, Joo Hee Kim
Summary: Human urine samples are valuable for diagnosing common clinical conditions due to their non-invasiveness and availability. However, traditional methods like the dipstick test have limitations, which can be overcome by biosensor technologies for point-of-care applications in urinalysis.
Article
Optics
Ke Chen, Hang Hu, Inho Song, Habtom B. Gobeze, Won-June Lee, Ashkan Abtahi, Kirk S. Schanze, Jianguo Mei
Summary: An optoelectronic synapse is created by adding a photoactive layer to an organic electrochemical transistor, allowing it to mimic the learning process of the human brain. These synapses can perceive and memorize visual information, making them ideal for applications such as bionic eyes or vision automation.
Article
Engineering, Biomedical
Dong-Hee Kang, Jun-Gyu Choi, Won-June Lee, Dongmi Heo, Sungrok Wang, Sungjun Park, Myung-Han Yoon
Summary: Biocompatible field-effect-transistor-based biosensors are proposed for the development of next-generation human-friendly electronics. The electrolyte-gated thin-film transistor made of solution-processed indium-gallium-zinc oxide (IGZO) semiconductors can directly interact with live cells at physiological conditions. The fabricated transistors exhibit good electrical performance and biocompatibility, making them suitable for direct cellular interfaces.
APL BIOENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Zain Ul Abideen, Jun-Gyu Choi, Jodie A. Yuwono, Won-June Lee, Krishnan Murugappan, Priyank Vijaya Kumar, David R. Nisbet, Thanh Tran-Phu, Myung-Han Yoon, Antonio Tricoli
Summary: Nanoscale heterojunction networks are promising functional materials for optoelectronic and photocatalytic devices. Optimizing their surface properties, especially surface defects, is a major challenge. This study reports on the effective engineering of the photocatalytic properties of nanoscale heterojunction networks through deep ultraviolet photoactivation.
ACS APPLIED MATERIALS & INTERFACES
(2023)
