Review
Chemistry, Physical
Y. Shi, X. Li, X. F. Sun, X. Shao, H. Y. Wang
Summary: Detection of ethanol is crucial in various fields due to its explosive, colorless and volatile nature. Metal oxide semiconductors (MOS) gas sensors, particularly those based on indium oxide (In2O3), have gained attention for their low cost and convenient detection. This paper summarizes the strategies used in the last decade to enhance the performance of In2O3-based gas sensors for ethanol detection, including morphology modification, doping, heterojunction construction, and the use of composite materials. The sensing mechanism for ethanol detection by gas sensors is also presented.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Analytical
Xinyu Liu, Cuiping Jia, Xin Liu, Jiabing Luo, Yan Zhou, Wenle Li, Shutao Wang, Jun Zhang
Summary: Ag-doped mesoporous In2O3 synthesized through hydrothermal and calcination methods exhibited enhanced sensitivity and adsorption performance in gas sensing, specifically towards ethanol.
Article
Chemistry, Analytical
Kelin Hu, Yuepeng Yang, Yujuan Hu, Wen Zeng, Ying Zhang, Mingwei Wang
Summary: In this study, CuO-loaded In2O3/CeO2 nanofiber heterojunctions were designed and prepared for trace CO gas detection. The materials were characterized, and the morphology of the nanofibers and the structure of the p-n heterojunctions were confirmed. The effect of morphology and structure on gas sensing performance was analyzed. Gas sensing tests showed that the sensor had a low optimum operating temperature of 70 degrees C, and a limit of detection as low as 50 ppb. The sensor exhibited a sensitive and linear response for CO gas concentrations ranging from 50 ppb to 10 ppm. Selectivity, humidity response, and long-term stability of the gas sensors were also tested. A mechanism for the enhanced CO gas sensing performance was proposed based on the structure of the materials.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Engineering, Electrical & Electronic
Anisha Bandyopadhyay, Kamalika Mandal, Vibhav Ambardekar, Debasish Das, S. B. Majumder
Summary: The study focused on the ethanol-sensing performance of CuO thick film fabricated by electrophoretic deposition (EPD) technique, which showed high response %, quick response and recovery time, and stable baseline resistance in static ambient. The EPD-grown thick film CuO sensor exhibited characteristics constant response time for different test gas concentrations, and activation energies of transduction and first-order kinetics were estimated through theoretical analysis.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2021)
Article
Materials Science, Multidisciplinary
Srinivasa Rao Sriram, Nagaraju Pothukanuri, Saidi Reddy Parne, Damodar Reddy Edla
Summary: Undoped and vanadium-doped tungsten trioxide nanocrystalline thin films were prepared using spray pyrolysis. The films were characterized for their micro-structural, topographical, optical and chemical properties. The results showed that the vanadium-doped film had a higher gas-sensing response to ethanol vapor compared to the undoped film.
ECS JOURNAL OF SOLID STATE SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
He Wang, Sirui Li, Hang Zhu, Shaoyuan Yu, Tianye Yang, Hongwei Zhao
Summary: In this study, a metal organic framework (MOF) derived bayberry-like In2O3 architectures gas sensor was prepared for the detection of trimethylamine (TMA) hazardous gases. The sensor exhibited a low operating temperature, high response value, fast response speed, and good selectivity and stability. The gas-sensing mechanism was discussed, attributing the excellent performance to the unique MOF-derived architecture and abundance of oxygen vacancies. With its excellent gas sensitivity, the sensor has potential applications in TMA gas detection, seafood freshness detection, and renal disease detection.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Nanoscience & Nanotechnology
Shi Kun Wang, Ao Chen Wang, Chao Yue Zhang, Qian Yu Liu, Jun Di Cheng, Yan Chun Wang, Xiu Ping Gao, Qing Feng Xie, Zhen Xing Zhang, Geng Zhi Sun, Xiao Jun Pan, Jin Yuan Zhou
Summary: A sandwich-structured hollow nanofiber material, In2S3/In2O3/In2S3 (ISOS HNF), was designed using electrospinning and postvulcanization treatments. The ISOS HNF material effectively overcomes the blocking effect in core-shell heterojunction sensors, and shows improved gas response due to the double In2S3/In2O3 heterointerfaces and the porous In2S3 coatings that enhance gas diffusion.
ACS APPLIED NANO MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
P. K. Shihabudeen, Ayan Roy Chaudhuri
Summary: The study found that the ethanol sensing performance of N-doped Indium oxide thin films is strongly dependent on their microstructure, with adsorption heat being a key factor influencing ethanol sensing response.
JOURNAL OF MATERIALS RESEARCH
(2021)
Article
Engineering, Electrical & Electronic
Ke Zhang, Yu Shen, Zhongde Lin, Zhenbiao Dong
Summary: The reasonable adjustment of morphology and surface modification with precious metals are effective methods to enhance gas sensitive properties. Gold-loaded mesoporous In2O3 nanoparticles show ultra-high sensitivity to ethanol detection, with improved activation energy, accelerated oxygen diffusion, and increased oxygen content due to electron sensitization and chemical sensitization of gold nanoparticles. Operating temperature, response and recovery time, selectivity, and stability are also relatively better with gold-loaded mesoporous In2O3 materials, making them ideal for ethanol detection in gas sensors.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Zambaga Otgonbayar, Young Jun Joo, Kwang Youn Cho, Sang Yul Park, Kwang Youl Park, Won-Chun Oh
Summary: A gas sensing test was conducted using a SCISO nanocomposite, which showed good performance under various temperature conditions. The physical and chemical properties of the nanocomposite were analyzed, and it was found that they were related to the electron density, charge transfer, and separation properties of the sensor layer. Among them, SCISO105 nanocomposite exhibited a strong response to CO2 and CH4 gases.
JOURNAL OF MATERIALS CHEMISTRY C
(2022)
Article
Engineering, Electrical & Electronic
Ke Zhang, Yu Shen, Yunsheng Li, Wenrui Zhang
Summary: This study successfully synthesized ZnO@In2O3 heterojunction nanocomposites with ultra-sensitive response to ethanol. The unique structure and characteristics of the composites contribute to their excellent gas sensing properties, including improved sensitivity, reduced energy consumption, and excellent repeatability and stability.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2022)
Article
Chemistry, Analytical
Amanzhol Turlybekuly, Madina Sarsembina, Almagul Mentbayeva, Zhumabay Bakenov, Baktiyar Soltabayev
Summary: A highly sensitive N2O gas sensor operating at room temperature has been developed using CuO/TiO2 heterojunctioned nano-interfaces, demonstrating outstanding response and recovery times and an excellent detection limit at ultra-low concentrations.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Analytical
Jingyu Zhang, Meng Kong, Kai Li, Xi Chen, Xin Li, Lu Yue, Xiuli Yang, Rongfeng Guan, Wenhui Zhang
Summary: Hierarchical S-doped In2O3 networks were synthesized with graphene oxide as a template and annealed. The effects of graphene oxide and annealing temperature on the morphology and phase of the samples were investigated. The hierarchical S-doped In2O3 networks consisted of nanosheets and microspheres assembled with nanowires and nanoparticles. The annealed hierarchical S-doped In2O3 networks at 500 degrees C showed the highest response (Ra/Rg) of 74.4 towards 50 ppm ethanol at 180 degrees C, which was approximately 2 times higher than that of S-doped In2O3 micro pompons prepared without graphene oxide. Moreover, the hierarchical In2O3 networks exhibited excellent selectivity and good stability to ethanol, which may be attributed to their unique hierarchical networks, high specific surface area (295.23 m2/g), and sulfur doping.
SENSORS AND ACTUATORS B-CHEMICAL
(2023)
Article
Chemistry, Physical
Xiaohu Wang, Shichao Wang, Huiyong Wang, Gaoqun Qiao, Wendi Liu, Ya Xiong, Jian Tian, Nannan Wu, Xinzhen Wang
Summary: The space charge region formed through electron transfer at the heterointerface in spherical heterostructure materials is beneficial for enhanced gas sensing performance. The positions of the two materials in the spherical structure have a significant influence on its performance. By investigating the effects of electron transfer direction, it was found that the structural design and electron transfer direction play important roles in the gas sensing properties of heterostructure materials.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Chao Shen, Ning Xu, Rongfeng Guan, Lu Yue, Wenhui Zhang
Summary: In2O3 spheres were successfully prepared using a nitric acid-assisted solvothermal method, with the morphology and structure of the products controlled by the nitric acid content. The sensing performance of In2O3 was enhanced by the addition of nitric acid, particularly with In2O3 spheres with partial broken structures showing a high response to ethanol and good selectivity and stability at 250 degrees C.
Article
Environmental Sciences
Ting Zhao, Ruifeng Qian, Guanda Zhou, Yu Wang, Wan In Lee, Jia Hong Pan
Summary: The strategic integration of membrane water filtration with semiconductor photocatalysis provides deep purification with self-cleaning capability. Mesoporous WO3/TiO2 spheres show superior photocatalytic activity and high flux, making them promising for concurrent membrane filtration and solar photocatalysis.
Article
Environmental Sciences
Hye Jin Kang, Dong Ii Won, Yeongsu Lim, Jeongho Kim, Wan In Lee
Summary: The study found that Pt deposition greatly enhances the photocatalytic activity of ATO/TiO2, while Au or Ag depositions have less significant effects. Spectroscopic analysis indicated that Pt is most effective in scavenging electrons from the ATO CB. Pt/ATO/TiO2 produced significantly more CO2 than other catalysts, suggesting that Pt deposition can suppress charge recombination pathways effectively.
Article
Computer Science, Information Systems
Jiho Jeong, S. I. M. M. Raton Mondol, Yeon Wook Kim, Sangmin Lee
Summary: An effective finetuning and augmentation ASR model is proposed in this study, targeting non-standard speech of cochlear implant (CI) patients, which achieved a 62% improvement in character error rate compared to the basic method.
Article
Chemistry, Analytical
Yeon-Wook Kim, Woo-Hyeong Cho, Kyu-Sung Kim, Sangmin Lee
Summary: In this study, a state-of-the-art conformer model was introduced in human activity recognition (HAR) to improve the performance of transformer-based HAR models. The proposed conformer-based model showed better performance than baseline models and previous algorithms that do not use recurrent neural network (RNN) series.
Article
Nanoscience & Nanotechnology
Sarnai Puntsagdorj, Agni Raj Koirala, Jargalsaikhan Gombovanjil, Nguyen Nguyen Khanh, Sang Do Sung, Wan In Lee, Kyung Byung Yoon
Summary: A facile stamping method was used to assemble ordered arrays of mesoporous WO3 micropillars, resulting in the preparation of a series of WO3 heterostructural bilayer photoanodes. The 2.5/7.5 photoanode displayed a higher photocurrent density compared to a plain WO3 sheet, due to increased charge carrier density and other beneficial factors.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Hyeon-Seo Choi, Yu-Na Kim, Seungyeon Hong, Bowen Yang, Jiajia Suo, Ji-Youn Seo, Seok Joon Kwon, Anders Hagfeldt, Hyo Jung Kim, Wan In Lee, Hui-Seon Kim
Summary: Surface passivation using a mixed salt has been shown to improve the performance and stability of perovskite solar cells. The length of the alkyl chain in the mixed salt can manipulate the crystal formation dynamics and enhance the (001) plane. The enhanced crystal orientation during surface recrystallization reduces trap density and suppresses charge recombination, leading to an increase in open-circuit voltage and fill factor.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
So-Yeon Ju, Wan In Lee, Hui-Seon Kim
Summary: This study introduces the strategy of strain control into perovskite solar cells, showing that applying compressive strain can improve the long-term photovoltaic performance. The compressive strain-induced perovskite film exhibits relatively constant absorbance spectra, while the film without strain control gradually decays and develops an Urbach tail. Furthermore, the device without strain control displays unreliable and overestimated fill factor and conversion efficiency after long-term storage, whereas the compressive strain-induced device shows a stable performance with a 16% increase in fill factor over 911 hours.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Biophysics
Yeon Wook Kim, Woo Hyeong Cho, Kyu Sung Kim, Sangmin Lee
Summary: In this study, the performance of the human activity recognition algorithm was improved by introducing an oversampling technique-based data augmentation algorithm and using a stacking ensemble model for classification. The proposed model achieved better results compared to previous studies.
JOURNAL OF MECHANICS IN MEDICINE AND BIOLOGY
(2022)
Article
Health Care Sciences & Services
S. I. M. M. Raton Mondol, Hyun Ji Kim, Kyu Sung Kim, Sangmin Lee
Summary: The novel application of a neural network technique in fitting hearing aids has been investigated in this study to minimize the discrepancy between initial fitting and optimal preference. The algorithm designed to learn individual users' hearing preferences demonstrates high efficiency, even with or without additional features. Furthermore, the results show that the algorithm outperforms the fitting software of Company A, indicating its potential for improving fitting satisfaction and benefiting the hearing-impaired community.
JOURNAL OF HEALTHCARE ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
You Jin Park, Young In Jeon, In Seok Yang, Hyunsue Choo, Woo Seok Suh, So-Yeon Ju, Hui-Seon Kim, Jia Hong Pan, Wan In Lee
Summary: Novel TiO2 nanorods with different lengths are synthesized under a basic environment and applied as the electron transporting layer for perovskite solar cells. The nanorods exhibit superior photovoltaic performance compared to conventional TiO2 nanoparticles. Specifically, TiO2 nanorods with a length of 110 nm show the highest efficiency and improved long-term stability. The advantages of nanorod structures in the device and the suppression of charge recombination are discussed.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Chemistry, Physical
Yu-Na Kim, Ju-Hee Jo, Jeongho Kim, Hui-Seon Kim, Wan In Lee
Summary: Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) is commonly used as a dopant in 2,2',7,7'-tetrakis[N,N-di(4-methoxyphenyl)amino]-9,9'-spirobifluor-ene (spiro-MeOTAD), but it results in poor thermal stability. Recently, zinc(II) bis(trifluoromethanesulfonyl)imide (Zn(TFSI)2) has been proposed as a potential replacement for LiTFSI. This study explores the use of Zn(TFSI)2 as a dopant for spiro-MeOTAD to investigate the thermal stability of perovskite solar cells (PSCs).
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Sarnai Puntsagdorj, Agni Raj Koirala, Jargalsaikhan Gombovanjil, Nguyen Nguyen Khanh, Sang Do Sung, Wan In Lee, Kyung Byung Yoon
Summary: A facile stamping method was developed to assemble ordered arrays of mesoporous WO(3 )micropillars, and heterostructural bilayer photoanodes with different layer structures were successfully prepared. Among them, the 2.5/7.5 exhibited a higher photocurrent density, which can be attributed to multiple factors.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Analytical
Yeon-Wook Kim, Kyung-Lim Joa, Han-Young Jeong, Sangmin Lee
Summary: This study utilized wearable technology and deep learning algorithms to improve the evaluation performance of the Berg Balance Scale, finding the optimal model combination through testing different structures.
Proceedings Paper
Acoustics
Seongbin Kim, Gyuwan Kim, Seongjin Shin, Sangmin Lee
Summary: End-to-end approaches are proposed to improve spoken language understanding systems by utilizing textual knowledge distillation methods. The study enhances performance, especially in low-resource scenarios, through data augmentation techniques, achieving state-of-the-art accuracy on Fluent Speech Commands dataset. Empirical studies confirm the importance of all used methods in achieving optimal performance for spoken language understanding.
2021 IEEE INTERNATIONAL CONFERENCE ON ACOUSTICS, SPEECH AND SIGNAL PROCESSING (ICASSP 2021)
(2021)
Article
Chemistry, Physical
Jin Woo Park, Yeongsu Lim, Kyung-Yeon Doh, Min Tai Jung, Young In Jeon, In Seok Yang, Hyeon-seo Choi, Jeongho Kim, Donghwa Lee, Wan In Lee
Summary: Cu-doped Ag2BiI5 powders were synthesized and used as light absorbers in solar cells, leading to a notable increase in power conversion efficiency. The enhancement was mainly attributed to the significant increase in light absorption caused by Cu doping. Additionally, Cu doping did not affect the stability of Ag2BiI5 under high humidity conditions.
SUSTAINABLE ENERGY & FUELS
(2021)
