Article
Materials Science, Multidisciplinary
I Derkaoui, M. Khenfouch, I Boukhoubza, M. Achehboune, R. Hatel, B. M. Mothudi, I Zorkani, A. Jorio, M. Maaza
Summary: The study demonstrates that controlling growth time and annealing treatment significantly affects the physico-chemical properties of vanadium oxides nanostructures, including structure, size, morphology, and electrical conductivity. The VO-NSs thin films exhibit clear orientation within monoclinic, tetragonal, and orthorhombic structures, and are suitable for various applications, particularly energy storage devices.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2021)
Article
Chemistry, Physical
Kuo-Chuan Chang, Chia-Jyi Liu
Summary: BiCuSeO demonstrates remarkable low thermal conductivity among oxides, with Cu atoms playing a more significant role in reducing lattice thermal conductivity than the lone pair of Bi3+ and point defects brought about by elemental doping.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Materials Science, Ceramics
Bangzhi Ge, Ruoyan Li, Guohao Wang, Menghua Zhu, Chongjian Zhou
Summary: This article discusses the strategies for optimizing the performance of oxide thermoelectric ceramics, including electrical optimization and lattice thermal suppression. The authors point out that the large electronegativity difference between the metal and O ions in oxide leads to electron localization and strong bond energy, limiting the improvement of their thermoelectric performance. To address this issue, the authors propose a series of optimization strategies and predict potential breakthroughs in the future.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Engineering, Environmental
Siyao Cheng, Xihao Pan, Aming Xie, Jiaoyan Shi, Qian Qiu, Cheng Zhang, Wei Dong, Xiaoliang Qi
Summary: By utilizing a modified Zn/HCl system for controlled hydrogenation of transition metal oxides (TMO), the research shows a significant improvement in the electromagnetic absorption (EMA) performance of TMO. The study reveals a close relationship between EMA property and hydrogenation degree, with potential for efficient tuning through hydrogenation control. These findings suggest that enhanced EMA performance in hydrogenated TMO is attributed to changes in band structure leading to increased electrical conductivity.
CHEMICAL ENGINEERING JOURNAL
(2021)
Article
Materials Science, Multidisciplinary
Rui Wang, Ralf Moos
Summary: A new method has been developed for measuring the electrical conductivity of semiconductor specimens, especially ceramics at high temperatures, without the need for accurate electrode preparation. The method involves processing an image of the specimen to a 3D model, calculating a form factor with finite element simulation, and deriving the actual conductivity using measured resistance. Experimental results have validated the method within a certain range of conductivity.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Materials Science, Ceramics
Marian Kubisztal
Summary: High-entropy ceramic oxide with the spinel structure and chemical composition Mn0.62(2)Fe0.62 (2)Ni0.60(3)Co0.58(2)Zn0.58(3)O4 was prepared using co-precipitation technique and low-temperature sintering process. The electrical conductivity variation in the temperature range of 120 K to 400 K was analyzed using theoretical models. It was found that the material exhibited a high temperature coefficient of resistance and a significant magnetoresistance coefficient.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Multidisciplinary
Amanda Guenther, Hilger Lohringer, Dirk Mueller, Elmar Schmidbauer, Christa Springsklee
Summary: Impedance spectroscopy was used to distinguish between bulk and grain boundary effects on polycrystalline VO2 samples near the metal-insulator transition temperature. While there is extensive literature on the electrical properties of VO2 thin films and nanowires, there is a lack of studies separating bulk and grain boundary effects. The structure of grain boundaries in polycrystalline samples is different from that in macroscopic samples, but provides valuable information on electrical conduction. Grain boundary processes in VO2 samples could be measured at room temperature to the transition temperature, while bulk properties and grain boundary conduction could only be studied at low temperatures.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Materials Science, Ceramics
A. Sotelo, P. Amirkhizi, O. J. Dura, G. Garcia, A. C. Asensio, M. A. Torres, M. A. Madre, A. Kovalevsky, Sh Rasekh
Summary: The attrition-milling process was used to obtain small grain-size powders from Ce-doped CaMnO3 precursors. By reducing the atomic proportion of dopant and optimizing the sintering process, the material showed improved thermoelectric performances and high ZT values. This approach is promising for large-scale production of oxide-based thermoelectric modules.
CERAMICS INTERNATIONAL
(2023)
Review
Chemistry, Physical
Yue Huang, Ruiming Qiu, Wenchao Lian, Libin Lei, Tong Liu, Jihao Zhang, Yao Wang, Jianping Liu, Jin Huang, Fanglin Chen
Summary: This review summarizes five methods for determining the electrical conduction properties of mixed ionic-electronic conducting (MIEC) oxides and discusses their modifications considering electrode polarization and operation conditions. The application of these methods in assessing the conduction properties of triple ionic-electronic conducting (TIEC) oxides is highlighted, and the reliability and applicability of these methods are elaborated and compared.
JOURNAL OF POWER SOURCES
(2022)
Review
Green & Sustainable Science & Technology
Kar Woon Tan, Chun Man Yap, Ziyue Zheng, Choon Yian Haw, Poi Sim Khiew, Wee Siong Chiu
Summary: Solar steam generation using metal oxide semiconductors as photoabsorbers has received much attention due to its wide application and abundant energy source. This review investigates the nanostructure, synthesis method, and installation method of recently reported solar evaporators using metal oxide semiconductors. The importance of metal oxide semiconductor nanostructure in regulating photothermal efficiency is emphasized. Other considerations, such as cost, stability, reproducibility, recyclability, and regenerative ability, are suggested for future synthesized photoabsorbers. The divergent applications and challenges and opportunities of metal oxide solar steam generation are also discussed.
ADVANCED SUSTAINABLE SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Niranjan S. Ramgir, C. P. Goyal, Deepak Goyal, S. J. Patil, H. Ikeda, S. Ponnusamy, K. P. Muthe, A. K. Debnath
Summary: ZnO nanowires grown hydrothermally were successfully modified by an ultrathin layer of Al, resulting in an improved and highly selective NO2 sensor. The sensor film showed a linear dependence in the concentration range, with swift response kinetics and a decrease in resistance due to Al modification. The observed decrease in sensor resistance agreed well with the findings of work function studies, showing a decrease in work function with Al modification.
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
(2021)
Article
Chemistry, Multidisciplinary
Pavel V. Barkov, Olga E. Glukhova
Summary: This study investigates the impact of holey graphene with different neck widths on its electrical conductivity. It was found that the neck width can influence the conductivity and electronic energy gap of holey graphene, and demonstrated anisotropy in electrical conductivity.
Article
Materials Science, Multidisciplinary
Jiaqi Dong, Chuxuan Yan, Yingzhi Chen, Wenjie Zhou, Yu Peng, Yue Zhang, Lu-Ning Wang, Zheng-Hong Huang
Summary: Organic semiconductor nanostructures play an important role in enhancing photocatalytic activity and stability. By assembling nanostructures or nanocomposites, the optoelectronic properties and photocatalytic efficiency of organic semiconductors can be improved. Nanoparticles of different dimensions (0D, 1D, 2D) have distinct advantages, and the construction of heterogeneous interfaces facilitates charge separation. Organic semiconductor nanostructures are widely used in photocatalytic water splitting, CO2 reduction, pollutant decomposition, disinfection, and other applications.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Materials Science, Ceramics
Liang Xu, Lei Su, Hongjie Wang, Min Niu, Lei Zhuang, Kang Peng, Xingyu Fan, Hongfei Gao, De Lu
Summary: In this study, a series of high-entropy oxides were prepared to investigate the impact of incorporating heterovalent cations on thermal conductivity and phase stability. It was found that the high-entropy RE2(Y0.2Yb0.2Nb0.2Ta0.2Ce0.2)(2)O-7 oxides exhibit low thermal conductivity and high-temperature stability, making them potential candidates for thermal barrier coating materials.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Ceramics
Hao Sun, Bo Zhang, Qing Zhao, Yafei Liu, Ruifeng Wu, Su Zhang, Yanqing Li, Aimin Chang
Summary: This article investigates the photoluminescence and conductive properties of CaEuNbMoO8 solid solution ceramics and finds their potential applications in near-ultraviolet excited light-emitting diodes and thermistors.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Nanoscience & Nanotechnology
Diana Gaspar, Jorge Martins, Jose Tiago Carvalho, Paul Grey, Rogerio Simoes, Elvira Fortunato, Rodrigo Martins, Luis Pereira
Summary: The market for flexible, hybrid, and printed electronic systems is uncertain, but these systems are emerging daily, allowing for devices and systems that can be folded and stored in pockets. Cellulose-based modified nanopapers were developed as a physical support and gate dielectric layer for recyclable field-effect transistors (FETs). Impregnation of the nanopapers with sodium ions enabled low voltage FETs (<3 V), with high mobility (>10 cm2 V-1 s-1), current modulation (>105), and improved dynamic response. These transistors were successfully implemented into simple circuits such as inverters, showing clear discrimination between logic states. Besides improved electrical performance, these devices are a promising alternative for reliable, sustainable, and flexible electronics, even under stress conditions.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Energy & Fuels
Paulo Joaquim Nunes, Rui Francisco Pinto Pereira, Sonia Pereira, Maria Manuela Silva, Elvira Fortunato, Veronica de Zea Bermudez, Mariana Fernandes
Summary: Two di-ureasils with oxyethylene segments were prepared by the sol-gel method, doped with ionic liquid and lithium salt. The resulting films were translucent, flexible, hydrophobic, and had low surface roughness. The optimized sample exhibited good ionic conductivity and was used in prototype electrochromic devices with promising performance.
Review
Medicine, General & Internal
Maria Joao Meneses, Rita Susana Patarrao, Tomas Pinheiro, Ines Coelho, Nuno Carrico, Ana Carolina Marques, Artur Romao, Joao Nabais, Elvira Fortunato, Joao Filipe Raposo, Maria Paula Macedo
Summary: Diabetes is a heterogeneous and multifactorial disease, and besides glycemia and glycated hemoglobin, the evaluation of other biochemical parameters is necessary for better diagnosis and management. Indexes of insulin secretion, sensitivity/resistance, and metabolism have been developed to provide a more comprehensive view of individual metabolic states. New technologies, such as sensors and software applications, have the potential to improve diabetes diagnosis and management, empowering patients and simplifying disease management.
EUROPEAN JOURNAL OF CLINICAL INVESTIGATION
(2023)
Article
Nanoscience & Nanotechnology
Bo He, Gang He, Shanshan Jiang, Jiangwei Liu, Elvira Fortunato, Rodrigo Martins
Summary: Thin-film transistors based on metal oxide semiconductors are widely used in driving low-cost backplanes of active matrix liquid crystal displays. Solution-based 1D nanofiber networks have been proven to be a simpler and higher-throughput approach for transistor fabrication. Double channel heterojunction transistors composed of In2O3 and ZnO layers show high electron mobility and operational stability, which can be optimized by adjusting the stacking order and density of the layers.
ADVANCED ELECTRONIC MATERIALS
(2023)
Article
Chemistry, Analytical
Beatriz J. Coelho, Joana P. Neto, Barbara Sieira, Andre T. Moura, Elvira Fortunato, Rodrigo Martins, Pedro V. Baptista, Rui Igreja, Hugo Aguas
Summary: Microfluidic-based platforms are powerful tools for chemical and biological assays. The fusion of different microfluidic technologies has the potential to overcome limitations and enhance their strengths.
Article
Polymer Science
Beatriz J. Coelho, Joana V. Pinto, Jorge Martins, Ana Rovisco, Pedro Barquinha, Elvira Fortunato, Pedro V. Baptista, Rodrigo Martins, Rui Igreja
Summary: Poly(p-xylylene) derivatives, also known as Parylenes, have been extensively studied for their thermal, structural, and electrical properties. This article explores the application of Parylene C in various electronic devices, including transistors, capacitors, and digital microfluidic devices. The results show that Parylene C can be used as a dielectric, substrate, and encapsulation layer in transistors, producing high performance devices with steep transfer curves, low gate leak currents, and good mobilities. The study also demonstrates the functionality of Parylene C in MIM structures and its capability to enable faster droplet motion and nucleic acid amplification reactions in DMF devices.
Article
Chemistry, Multidisciplinary
Maria Leonor Matias, Ana S. Reis-Machado, Joana Rodrigues, Tomas Calmeiro, Jonas Deuermeier, Ana Pimentel, Elvira Fortunato, Rodrigo Martins, Daniela Nunes
Summary: A graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) heterostructure was synthesized through a fast and simple microwave-assisted method, and it showed excellent photocatalytic activity for the degradation of a recalcitrant azo dye under solar simulating light. The 30% g-C3N4/TiO2 heterostructure exhibited the best performance.
Article
Nanoscience & Nanotechnology
Luca Fabbri, Camilla Bordoni, Pedro Barquinha, Jerome Crocco, Beatrice Fraboni, Tobias Cramer
Summary: The disordered microscopic structure of amorphous semiconductors leads to the formation of band tails in the density of states (DOS), which greatly affect charge transport properties. Kelvin Probe Force Microscopy (KPFM) is a powerful technique to measure the DOS, but lacks a model to interpret KPFM spectroscopy data on amorphous semiconductors of finite thickness. In this study, an analytical solution to the Poisson equation is provided for a metal-insulator-semiconductor junction interacting with the atomic force microscope tip, allowing for the fitting of experimental data and obtaining DOS parameters. This method was demonstrated on Indium-Gallium-Zinc Oxide (IGZO) thin-film transistors (IGZO-TFTs) and showed good agreement with values obtained from photocurrent spectroscopy.
Article
Materials Science, Multidisciplinary
J. Figueira, R. M. Bonito, J. T. Carvalho, E. M. F. Vieira, C. Gaspar, Joana Loureiro, J. H. Correia, E. Fortunato, R. Martins, L. Pereira
Summary: Flexible thermal touch sensors were produced by optimizing ethyl cellulose and graphite flakes inks for screen-printing. The best electrical-TE output combination was achieved by printing two layers of the ink with 20 wt% of graphite on an office paper substrate. The results showed that the screen-printed graphite-based inks are highly suitable for flexible TE sensing applications.
FLEXIBLE AND PRINTED ELECTRONICS
(2023)
Review
Engineering, Electrical & Electronic
Maria Elias Pereira, Rodrigo Martins, Elvira Fortunato, Pedro Barquinha, Asal Kiazadeh
Summary: Neuromorphic computing is gaining popularity as a replacement for outdated technology in conventional computing systems. Artificial neural networks composed of memristor crossbars in hardware offer power, cost, and area-efficient in-memory computing and storage. Optoelectronic memristors (OEMs) can control resistive switching (RS) through both optical and electronic signals, solving crosstalk issues and providing a high-speed non-destructive method. This review summarizes recent advances in inorganic OEMs, analyzing the device structure and assessing their potential applications in logic gates, artificial neural networks, and artificial visual systems with consideration for their performance.
NEUROMORPHIC COMPUTING AND ENGINEERING
(2023)
Article
Chemistry, Analytical
Maria Joao Oliveira, Soraia Caetano, Ana Dalot, Filipe Sabino, Tomas R. Calmeiro, Elvira Fortunato, Rodrigo Martins, Eulalia Pereira, Miguel Prudencio, Hugh J. Byrne, Ricardo Franco, Hugo Aguas
Summary: Early and accurate detection of pathogenic microorganisms is crucial for diagnosis and patient outcomes. The combination of a polystyrene-based microfluidic device and Surface-Enhanced Raman Spectroscopy shows excellent sensitivity and specificity in detecting malaria. The system can be easily adapted for other pathogens and has the potential for early diagnosis of infectious diseases.
