Pub Date : 2024-09-25DOI: 10.1007/s13391-024-00523-x
Donghyun Shin, Hyunji Kim, Joseph Ngugi Kahiu, Samuel Kimani Kihoi, Ho Seong Lee
In this study, we aimed to synthesize bulk Cr2Te3 and evaluate its thermoelectric properties. Previously, Cr2Te3 with a layered structure has primarily been synthesized in thin film form for studies that focused on its magnetic properties. The intrinsic layered structure of Cr₂Te₃ can contributes to its low lattice thermal conductivity. Our experimental results confirmed the successful synthesis of a homogeneous single-phase specimen and revealed a significantly low lattice thermal conductivity of 0.31 W/mK at 673 K. Additionally, we explored the substitution of titanium and germanium at chromium sites as a method to enhance thermoelectric performance, achieving a notable increase in the power factor.
{"title":"Thermoelectric Characteristics of Bulk Cr2Te3 with Low Lattice Thermal Conductivity","authors":"Donghyun Shin, Hyunji Kim, Joseph Ngugi Kahiu, Samuel Kimani Kihoi, Ho Seong Lee","doi":"10.1007/s13391-024-00523-x","DOIUrl":"10.1007/s13391-024-00523-x","url":null,"abstract":"<div><p>In this study, we aimed to synthesize bulk Cr<sub>2</sub>Te<sub>3</sub> and evaluate its thermoelectric properties. Previously, Cr<sub>2</sub>Te<sub>3</sub> with a layered structure has primarily been synthesized in thin film form for studies that focused on its magnetic properties. The intrinsic layered structure of Cr₂Te₃ can contributes to its low lattice thermal conductivity. Our experimental results confirmed the successful synthesis of a homogeneous single-phase specimen and revealed a significantly low lattice thermal conductivity of 0.31 W/mK at 673 K. Additionally, we explored the substitution of titanium and germanium at chromium sites as a method to enhance thermoelectric performance, achieving a notable increase in the power factor.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"70 - 78"},"PeriodicalIF":2.1,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-24DOI: 10.1007/s13391-024-00522-y
Kwan-Jun Heo, Jae-Yun Lee, Gergely Tarsoly, Sung-Jin Kim
This study investigates the utilization of MoO3 precursors to enhance the electrical properties and stability of In2O3 TFTs based on eco-friendly aqueous solutions. Specifically, MoO3 doped In2O3 (Mo-In2O3) TFTs were examined in this research. The Mo cation, hydroxide anion, and oxide radical of the MoO3 precursor provide free electrons to the In2O3 thin film, reducing the trap site between the semiconductor interface, the semiconductor and the insulator, and improving the stability of the device by adjusting the oxygen vacancy. To verify the change in the electrical properties of In2O3 TFT due to MoO3 doping, measurements of electron mobility after 30 days confirmed that In2O3 TFT electron mobility decreased by more than 80%, whereas Mo-In2O3 TFT electron mobility remained stable. PBS and NBS reliability evaluations confirmed that the Vth change of Mo- In2O3 TFT was less than that of In2O3 TFT. (In2O3 TFT PBS: 5.55 V, NBS: 0.33 V, Mo-In2O3 TFT PBS: 4.04 V, NBS: 0.10 V). In order to confirm the interface change of In2O3 film according to MoO3 Doping, the difference in surface roughness was measured using an AFM and found to be within 4%. In addition, the doping effect of the active layer was verified through changes in oxygen species in XPS analysis. To demonstrate its application as an active electronic device, a Mo-In2O3 TFT based resistance load inverter was evaluated, and the voltage transfer curve and excellent inversion characteristics of the inverter were confirmed under various VDD conditions.
Graphical Abstract
Kwan-Jun Heo et al., multi-functional molybdenum oxide doping to improve the electrical characteristics of indium oxide thin film transistors
{"title":"Multi-Functional Molybdenum Oxide Doping to Improve the Electrical Characteristics of Indium Oxide Thin Film Transistors","authors":"Kwan-Jun Heo, Jae-Yun Lee, Gergely Tarsoly, Sung-Jin Kim","doi":"10.1007/s13391-024-00522-y","DOIUrl":"10.1007/s13391-024-00522-y","url":null,"abstract":"<div><p>This study investigates the utilization of MoO<sub>3</sub> precursors to enhance the electrical properties and stability of In<sub>2</sub>O<sub>3</sub> TFTs based on eco-friendly aqueous solutions. Specifically, MoO<sub>3</sub> doped In<sub>2</sub>O<sub>3</sub> (Mo-In<sub>2</sub>O<sub>3</sub>) TFTs were examined in this research. The Mo cation, hydroxide anion, and oxide radical of the MoO<sub>3</sub> precursor provide free electrons to the In<sub>2</sub>O<sub>3</sub> thin film, reducing the trap site between the semiconductor interface, the semiconductor and the insulator, and improving the stability of the device by adjusting the oxygen vacancy. To verify the change in the electrical properties of In<sub>2</sub>O<sub>3</sub> TFT due to MoO<sub>3</sub> doping, measurements of electron mobility after 30 days confirmed that In<sub>2</sub>O<sub>3</sub> TFT electron mobility decreased by more than 80%, whereas Mo-In<sub>2</sub>O<sub>3</sub> TFT electron mobility remained stable. PBS and NBS reliability evaluations confirmed that the Vth change of Mo- In<sub>2</sub>O<sub>3</sub> TFT was less than that of In<sub>2</sub>O<sub>3</sub> TFT. (In<sub>2</sub>O<sub>3</sub> TFT PBS: 5.55 V, NBS: 0.33 V, Mo-In<sub>2</sub>O<sub>3</sub> TFT PBS: 4.04 V, NBS: 0.10 V). In order to confirm the interface change of In<sub>2</sub>O<sub>3</sub> film according to MoO<sub>3</sub> Doping, the difference in surface roughness was measured using an AFM and found to be within 4%. In addition, the doping effect of the active layer was verified through changes in oxygen species in XPS analysis. To demonstrate its application as an active electronic device, a Mo-In<sub>2</sub>O<sub>3</sub> TFT based resistance load inverter was evaluated, and the voltage transfer curve and excellent inversion characteristics of the inverter were confirmed under various <i>V</i><sub><i>DD</i></sub> conditions.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div><div><p>Kwan-Jun Heo et al., multi-functional molybdenum oxide doping to improve the electrical characteristics of indium oxide thin film transistors</p></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"9 - 21"},"PeriodicalIF":2.1,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142925574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-15DOI: 10.1007/s13391-024-00519-7
Dongwook Kim, Joel Ndikumana, Hyeonju Lee, Seullee Lee, Youngjun Yun, Jaehoon Park
In this study, we examined the impact of crystal domain on the electrical performance and durability of flexible organic thin-film transistors (OTFTs). To analyze this, we fabricated the OTFTs on a polyimide substrate using 2,8-difluoro-5,11bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) as the organic semiconductor. To examine the influence of the film morphology and crystallinity on the electrical characteristics of OTFTs, we dissolved diF-TES-ADT in chlorobenzene and toluene solvent, annealed it at different temperatures, and then evaluated its electrical performances. The optimum annealing temperature of the diF-TES-ADT OTFTs was determined through the comprehensive analysis of the electrical parameters. The film morphology and crystallinity of organic semiconductor as a function of temperature were examined using the technical measurement analysis such as the atomic force measurement, X-ray diffraction and polarized optic microscopy. Furthermore, we demonstrated the electrical degradation of the device under prolonged bending cycles and observed the effect of bending stress on the electrical performance of OTFTs. The size of the crystalline domain and surface morphology indicated a slower deterioration of OTFT performance with an increase in the number of bending cycles. It was approved that the crystal grain size and morphology of organic semiconductor may not be critical factors determining the electrical performance of OTFTs, however, the electrical durability against bending stress was significantly degraded by these factors. We speculate that the smaller grain sizes and directionally-grown crystalline structure are highly vulnerable to bending stress, resulting in increased occurrence of void cracks and structural defects.
{"title":"Impact of Crystal Domain on Electrical Performance and Bending Durability of Flexible Organic Thin-Film Transistors with diF-TES-ADT Semiconductor","authors":"Dongwook Kim, Joel Ndikumana, Hyeonju Lee, Seullee Lee, Youngjun Yun, Jaehoon Park","doi":"10.1007/s13391-024-00519-7","DOIUrl":"10.1007/s13391-024-00519-7","url":null,"abstract":"<div><p>In this study, we examined the impact of crystal domain on the electrical performance and durability of flexible organic thin-film transistors (OTFTs). To analyze this, we fabricated the OTFTs on a polyimide substrate using 2,8-difluoro-5,11bis(triethylsilylethynyl)anthradithiophene (diF-TES-ADT) as the organic semiconductor. To examine the influence of the film morphology and crystallinity on the electrical characteristics of OTFTs, we dissolved diF-TES-ADT in chlorobenzene and toluene solvent, annealed it at different temperatures, and then evaluated its electrical performances. The optimum annealing temperature of the diF-TES-ADT OTFTs was determined through the comprehensive analysis of the electrical parameters. The film morphology and crystallinity of organic semiconductor as a function of temperature were examined using the technical measurement analysis such as the atomic force measurement, X-ray diffraction and polarized optic microscopy. Furthermore, we demonstrated the electrical degradation of the device under prolonged bending cycles and observed the effect of bending stress on the electrical performance of OTFTs. The size of the crystalline domain and surface morphology indicated a slower deterioration of OTFT performance with an increase in the number of bending cycles. It was approved that the crystal grain size and morphology of organic semiconductor may not be critical factors determining the electrical performance of OTFTs, however, the electrical durability against bending stress was significantly degraded by these factors. We speculate that the smaller grain sizes and directionally-grown crystalline structure are highly vulnerable to bending stress, resulting in increased occurrence of void cracks and structural defects.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"1 - 8"},"PeriodicalIF":2.1,"publicationDate":"2024-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142264597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-12DOI: 10.1007/s13391-024-00521-z
Chang-Su Kim, Kookhan Kim, An-Seop Im, Sung-Su Kim, Jongmin Kim, Ji-Yong Eom
In this study, a high-energy-density electrode was fabricated by combining cobalt-free layered oxide (NM) with olivine LiFePO4 (LFP) nanoparticles. The resulting mixed all-cobalt-free cathode electrode effectively minimized electrode porosity by filling the interstitial spaces between the micron-sized layered-oxide particles with nanoscale LFP particles, significantly improving electrode density, and exhibiting excellent electrode conductivity. Furthermore, the composite electrode composed of NM and LFP achieved a volumetric capacity exceeding 600 mAh/cm− 3, comparable to that of typical layered oxide cathode materials, while also demonstrating enhanced cycle-life performance relative to electrodes composed solely of layered oxide or LFP. The enhanced electrochemical performance is attributed to the efficient lithium-ion and electron conduction facilitated by the intimate contact between NM and LFP particles, the suppression of NM particle degradation due to the relatively stable LFP particles on the NM surface, and the reduced particle fracture during roll-pressing. These improvements have been confirmed through electrochemical analyses and electrode observations.
{"title":"All-Cobalt-Free Layered/Olivine Mixed Cathode Material for High-Electrode Density and Enhanced Cycle-Life Performance","authors":"Chang-Su Kim, Kookhan Kim, An-Seop Im, Sung-Su Kim, Jongmin Kim, Ji-Yong Eom","doi":"10.1007/s13391-024-00521-z","DOIUrl":"10.1007/s13391-024-00521-z","url":null,"abstract":"<div><p>In this study, a high-energy-density electrode was fabricated by combining cobalt-free layered oxide (NM) with olivine LiFePO<sub>4</sub> (LFP) nanoparticles. The resulting mixed all-cobalt-free cathode electrode effectively minimized electrode porosity by filling the interstitial spaces between the micron-sized layered-oxide particles with nanoscale LFP particles, significantly improving electrode density, and exhibiting excellent electrode conductivity. Furthermore, the composite electrode composed of NM and LFP achieved a volumetric capacity exceeding 600 mAh/cm<sup>− 3</sup>, comparable to that of typical layered oxide cathode materials, while also demonstrating enhanced cycle-life performance relative to electrodes composed solely of layered oxide or LFP. The enhanced electrochemical performance is attributed to the efficient lithium-ion and electron conduction facilitated by the intimate contact between NM and LFP particles, the suppression of NM particle degradation due to the relatively stable LFP particles on the NM surface, and the reduced particle fracture during roll-pressing. These improvements have been confirmed through electrochemical analyses and electrode observations.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 6","pages":"799 - 806"},"PeriodicalIF":2.1,"publicationDate":"2024-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-11DOI: 10.1007/s13391-024-00520-0
Yeonjin Je, Sang-Soo Chee
Two-dimensional material, tellurium, composed of tellurium, has emerged as a promising material for NO2 gas sensing due to its superior intrinsic electrical conductivity and strong affinity to NO2. However, the majority of literature on tellurene-based gas sensors has primarily focused on NO2 detection performances under dry condition, despite the importance of considering humidity-dependent detection properties for practical gas sensing applications. Here, we explore NO2 detection properties of tellurene-based chemiresistive gas sensor devices under humidity environments at room temperature. The resultant tellurene synthesized via a hydrothermal route presents 2D flake-like morphologies with highly crystalline hexagonal structures. The obtained tellurene chemiresistive sensor devices exhibit a good NO2 gas response of 35% with a fast response time of 14 s, under dry conditions. Interestingly, our tellurene-based sensor devices also present the humidity-independent NO2 gas detection performances while achieving a fast response time. These outstanding detection performances are likely due to intrinsically superior electrical conductivity and structural stability of tellurene in air.
{"title":"High-speed and Sub-ppm Detectable Tellurene NO2 Chemiresistive Room-Temperature Sensor under Humidity Environments","authors":"Yeonjin Je, Sang-Soo Chee","doi":"10.1007/s13391-024-00520-0","DOIUrl":"10.1007/s13391-024-00520-0","url":null,"abstract":"<div><p>Two-dimensional material, tellurium, composed of tellurium, has emerged as a promising material for NO<sub>2</sub> gas sensing due to its superior intrinsic electrical conductivity and strong affinity to NO<sub>2</sub>. However, the majority of literature on tellurene-based gas sensors has primarily focused on NO<sub>2</sub> detection performances under dry condition, despite the importance of considering humidity-dependent detection properties for practical gas sensing applications. Here, we explore NO<sub>2</sub> detection properties of tellurene-based chemiresistive gas sensor devices under humidity environments at room temperature. The resultant tellurene synthesized via a hydrothermal route presents 2D flake-like morphologies with highly crystalline hexagonal structures. The obtained tellurene chemiresistive sensor devices exhibit a good NO<sub>2</sub> gas response of 35% with a fast response time of 14 s, under dry conditions. Interestingly, our tellurene-based sensor devices also present the humidity-independent NO<sub>2</sub> gas detection performances while achieving a fast response time. These outstanding detection performances are likely due to intrinsically superior electrical conductivity and structural stability of tellurene in air.</p><h3>Graphic Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"94 - 101"},"PeriodicalIF":2.1,"publicationDate":"2024-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142224575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-31DOI: 10.1007/s13391-024-00518-8
Guoqing Sun, Yafei Liu, Xuewen Liu
The assessment of the State of Health (SOH) of lithium-ion batteries is paramount to ensuring the safety and reliability of battery management systems. Numerous researchers have employed Equivalent Circuit Models (ECM) and data-driven methodologies to estimate SOH. Each methodology has its merits and drawbacks, yet their integration poses substantial challenges. This paper proposes a novel approach for SOH estimation that synthesizes ECM with data-driven techniques. Initially, parameters for a second-order ECM are identified utilizing the voltage rebound characteristics of lithium-ion batteries. Subsequently, a predictive model is established employing a Long Short-Term Memory (LSTM) neural network. Finally, features extracted from the ECM and the dataset are utilized as inputs for the LSTM neural network to predict SOH. The efficacy of the proposed technique is corroborated by datasets from NASA and CALCE. Results indicate that the novel method’s maximum Root Mean Square Error (RMSE) is confined to 0.79%, and the Mean Absolute Error (MAE) is limited to 0.47%. Compared to other methods, this approach exhibits faster convergence, higher precision, and enhanced generalizability.
{"title":"A Neural Network Approach for Health State Estimation of Lithium-Ion Batteries Incorporating Physics Knowledge","authors":"Guoqing Sun, Yafei Liu, Xuewen Liu","doi":"10.1007/s13391-024-00518-8","DOIUrl":"10.1007/s13391-024-00518-8","url":null,"abstract":"<div><p>The assessment of the State of Health (SOH) of lithium-ion batteries is paramount to ensuring the safety and reliability of battery management systems. Numerous researchers have employed Equivalent Circuit Models (ECM) and data-driven methodologies to estimate SOH. Each methodology has its merits and drawbacks, yet their integration poses substantial challenges. This paper proposes a novel approach for SOH estimation that synthesizes ECM with data-driven techniques. Initially, parameters for a second-order ECM are identified utilizing the voltage rebound characteristics of lithium-ion batteries. Subsequently, a predictive model is established employing a Long Short-Term Memory (LSTM) neural network. Finally, features extracted from the ECM and the dataset are utilized as inputs for the LSTM neural network to predict SOH. The efficacy of the proposed technique is corroborated by datasets from NASA and CALCE. Results indicate that the novel method’s maximum Root Mean Square Error (RMSE) is confined to 0.79%, and the Mean Absolute Error (MAE) is limited to 0.47%. Compared to other methods, this approach exhibits faster convergence, higher precision, and enhanced generalizability.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"21 1","pages":"119 - 133"},"PeriodicalIF":2.1,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-20DOI: 10.1007/s13391-024-00517-9
Sung Yong An, Boum Seock Kim
This study investigates methods to enhance the permeability of metal magnetic composites, crucial for the performance of thin film power inductors in high-frequency applications, such as those in contemporary smartphones operating in the MHz range. Traditional reliance on ferrite magnetic materials is eschewed in favor of metal magnetic materials combined with epoxy to create novel composites aimed at optimizing packing density and significantly increasing magnetic permeability. The impact on permeability is explored using four different metal powders: pure iron (FE), Fe-Si (FS), Fe-Si-B-C-Cr (AM), and Fe-Si-B-Nb-Cu (NC). The FE sample is produced using carbonyl iron powder, resulting in a particle size (D50) of 2.1 μm. The FS sample, produced through gas atomization, has a particle size of 17.5 μm, while the AM and NC samples, produced via water atomization, yield particle sizes (D50) of 19.4 μm and 23 μm, respectively. Analyses using X-ray diffraction (XRD) and Mösbauer spectroscopy reveal that FE and FS samples have crystalline structures, whereas AM and NC are amorphous. Scanning electron microscopy confirms the spherical shape of particles in all samples. Theoretical calculations, based on Ollendorff’s theory of permeability and Suzuki and Oshima’s models on packing fraction, suggest that a composite with a ratio of 8:1.2:0.8 and particle sizes of approximately 25 μm, 1.5 μm, and 0.1 μm, respectively, could achieve a permeability value of up to 138.1. This demonstrates the potential for achieving high permeability at MHz frequencies through strategic packing of voids with submicron and nanopowders, marking a significant advancement in the field of thin film power inductors.
{"title":"Enhanced Magnetic Permeability Through Improved Packing Density for Thin-Film Type Power Inductors for High-Frequency Applications","authors":"Sung Yong An, Boum Seock Kim","doi":"10.1007/s13391-024-00517-9","DOIUrl":"10.1007/s13391-024-00517-9","url":null,"abstract":"<div><p>This study investigates methods to enhance the permeability of metal magnetic composites, crucial for the performance of thin film power inductors in high-frequency applications, such as those in contemporary smartphones operating in the MHz range. Traditional reliance on ferrite magnetic materials is eschewed in favor of metal magnetic materials combined with epoxy to create novel composites aimed at optimizing packing density and significantly increasing magnetic permeability. The impact on permeability is explored using four different metal powders: pure iron (FE), Fe-Si (FS), Fe-Si-B-C-Cr (AM), and Fe-Si-B-Nb-Cu (NC). The FE sample is produced using carbonyl iron powder, resulting in a particle size (D50) of 2.1 μm. The FS sample, produced through gas atomization, has a particle size of 17.5 μm, while the AM and NC samples, produced via water atomization, yield particle sizes (D50) of 19.4 μm and 23 μm, respectively. Analyses using X-ray diffraction (XRD) and Mösbauer spectroscopy reveal that FE and FS samples have crystalline structures, whereas AM and NC are amorphous. Scanning electron microscopy confirms the spherical shape of particles in all samples. Theoretical calculations, based on Ollendorff’s theory of permeability and Suzuki and Oshima’s models on packing fraction, suggest that a composite with a ratio of 8:1.2:0.8 and particle sizes of approximately 25 μm, 1.5 μm, and 0.1 μm, respectively, could achieve a permeability value of up to 138.1. This demonstrates the potential for achieving high permeability at MHz frequencies through strategic packing of voids with submicron and nanopowders, marking a significant advancement in the field of thin film power inductors.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 6","pages":"733 - 744"},"PeriodicalIF":2.1,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-10DOI: 10.1007/s13391-024-00514-y
Yubo Yao, Hongfei Dai, Mengnan Ji, Ying Han, Bo Jiang, Chi Cheng, Xiaolei Song, Ying Song, Guangfeng Wu
Flexible strain sensors that combine high sensitivity and wide range are important for developing wearable electronics. In this paper, AgNWs/MXene/SEBS flexible strain sensor with high sensitivity and wide strain range was prepared using a thermoplastic elastomer (styrene-ethylene-butene-styrene) SEBS as the polymer matrix and AgNWs and MXene as the composite conductive fillers. The sensitivity of the AgNWs/MXene/SEBS sensor is significantly higher than that of the AgNWs/SEBS and MXene/SEBS sensors based on a single conductive filler. At 100% strain, the AgNWs/MXene/SEBS sensor has a sensitivity of 176.25. The sensor detects small strains of 0.5-5% as well as large strains of 5–50% with high linearity. The sensors remained stable after 200 cycles. The AgNWs/MXene/SEBS tensile sensors were subjected to array testing and finger bending recognition, and the sensors have promising applications in human motion monitoring.
{"title":"Flexible Strain Sensor Based on AgNWs/MXene/SEBS with High Sensitivity and Wide Strain Range","authors":"Yubo Yao, Hongfei Dai, Mengnan Ji, Ying Han, Bo Jiang, Chi Cheng, Xiaolei Song, Ying Song, Guangfeng Wu","doi":"10.1007/s13391-024-00514-y","DOIUrl":"10.1007/s13391-024-00514-y","url":null,"abstract":"<div><p>Flexible strain sensors that combine high sensitivity and wide range are important for developing wearable electronics. In this paper, AgNWs/MXene/SEBS flexible strain sensor with high sensitivity and wide strain range was prepared using a thermoplastic elastomer (styrene-ethylene-butene-styrene) SEBS as the polymer matrix and AgNWs and MXene as the composite conductive fillers. The sensitivity of the AgNWs/MXene/SEBS sensor is significantly higher than that of the AgNWs/SEBS and MXene/SEBS sensors based on a single conductive filler. At 100% strain, the AgNWs/MXene/SEBS sensor has a sensitivity of 176.25. The sensor detects small strains of 0.5-5% as well as large strains of 5–50% with high linearity. The sensors remained stable after 200 cycles. The AgNWs/MXene/SEBS tensile sensors were subjected to array testing and finger bending recognition, and the sensors have promising applications in human motion monitoring.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 6","pages":"684 - 693"},"PeriodicalIF":2.1,"publicationDate":"2024-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141920465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-09DOI: 10.1007/s13391-024-00516-w
Young-Woong Song, Junseo Lee, Sein Lee, Wooho Ham, Jeong Hyun Yoon, Jeong-Min Park, Taehoon Sung, Jang-Yeon Kwon
With the advent of artificial intelligence (AI), automated machines could replace human labor in the near future. Nevertheless, AI implementation is currently confined to environments with huge power supplies and computing resources. Artificial neural networks are only implemented at the software level, which necessitates the continual retrieval of synaptic weights among devices. Physically constructing neural networks using emerging nonvolatile memories allows synaptic weights to be directly mapped, thereby enhancing the computational efficiency of AI. While resistive switching memory (RRAM) represents superior performances for in-memory computing, unresolved challenges persist regarding its nonideal properties. A significant challenge to the optimal performance of neural networks using RRAMs is the nonlinear conductance update. Ionic hopping of oxygen vacancy species should be thoroughly investigated and controlled for the successful implementation of RRAM-based AI acceleration. This study dopes tantalum oxide-based RRAM with aluminum, thus improving the nonlinear conductance modulation during the resistive switching process. As a result, the simulated classification accuracy of the trained network was significant improved.
{"title":"Linear Conductance Modulation in Aluminum Doped Resistive Switching Memories for Neuromorphic Computing","authors":"Young-Woong Song, Junseo Lee, Sein Lee, Wooho Ham, Jeong Hyun Yoon, Jeong-Min Park, Taehoon Sung, Jang-Yeon Kwon","doi":"10.1007/s13391-024-00516-w","DOIUrl":"10.1007/s13391-024-00516-w","url":null,"abstract":"<div><p>With the advent of artificial intelligence (AI), automated machines could replace human labor in the near future. Nevertheless, AI implementation is currently confined to environments with huge power supplies and computing resources. Artificial neural networks are only implemented at the software level, which necessitates the continual retrieval of synaptic weights among devices. Physically constructing neural networks using emerging nonvolatile memories allows synaptic weights to be directly mapped, thereby enhancing the computational efficiency of AI. While resistive switching memory (RRAM) represents superior performances for in-memory computing, unresolved challenges persist regarding its nonideal properties. A significant challenge to the optimal performance of neural networks using RRAMs is the nonlinear conductance update. Ionic hopping of oxygen vacancy species should be thoroughly investigated and controlled for the successful implementation of RRAM-based AI acceleration. This study dopes tantalum oxide-based RRAM with aluminum, thus improving the nonlinear conductance modulation during the resistive switching process. As a result, the simulated classification accuracy of the trained network was significant improved.</p><h3>Graphical Abstract</h3>\u0000<div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 6","pages":"725 - 732"},"PeriodicalIF":2.1,"publicationDate":"2024-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141923615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, nitrogen-doped carbon (NC) coated tens nanometer hydrangea macrophylla-like CeO2(CeO2-NC) was synthesized by simple hydrothermal and polymeric calcination approach. Samples are characterised by SEM, Raman spectroscopy, XPS, etc. CeO2-NC shows an initial potential of 0.90V (vs. Ag/AgCl) in 9.5 M H3PO4. In addition, the CeO2-NC composite also exhibits a high limiting current (6.25 mA mg−1). CeO2-NC effectively combines the high initial potential of CeO2 with the high limiting current of NC. Moreover, a hybrid proton battery assembled with CeO2-NC composite as the cathode catalyst and MoO3 (1 mg) as anode catalyst can produce a high capacity of 261.7 mAh at 1 A g−1. The hybrid battery also exhibits excellent catalytic stability. After 1000 cycles at a high current density of 15 A g−1, the capacity of the battery still remains 125.0 mAh, with a retention rate of approximately 90.9%. The improvement in battery performance is due to the use of NC to coat CeO2, which improves the limiting current and durability of the electrode. The presented hybrid proton batteries have further enriched the application of electrochemical energy storage devices, and the preliminary exploration of cathode catalysts significantly improved the catalytic performance of ORR under acidic conditions.
{"title":"Hydrangea Macrophylla-Like CeO2 Coated by Nitrogen-Doped Carbon as Highly Efficient ORR Cathode Catalyst in a Hybrid Proton Battery","authors":"Rui Zhang, Huizhen Si, Qizhao Hu, Yangbo Cui, Shangbin Sang, Kaiyu Liu, Hongtao Liu, Qiumei Wu, Xianggong Zhang","doi":"10.1007/s13391-024-00515-x","DOIUrl":"10.1007/s13391-024-00515-x","url":null,"abstract":"<div><p>In this paper, nitrogen-doped carbon (NC) coated tens nanometer hydrangea macrophylla-like CeO<sub>2</sub>(CeO<sub>2</sub>-NC) was synthesized by simple hydrothermal and polymeric calcination approach. Samples are characterised by SEM, Raman spectroscopy, XPS, etc. CeO<sub>2</sub>-NC shows an initial potential of 0.90V (vs. Ag/AgCl) in 9.5 M H<sub>3</sub>PO<sub>4</sub>. In addition, the CeO<sub>2</sub>-NC composite also exhibits a high limiting current (6.25 mA mg<sup>−1</sup>). CeO<sub>2</sub>-NC effectively combines the high initial potential of CeO<sub>2</sub> with the high limiting current of NC. Moreover, a hybrid proton battery assembled with CeO<sub>2</sub>-NC composite as the cathode catalyst and MoO<sub>3</sub> (1 mg) as anode catalyst can produce a high capacity of 261.7 mAh at 1 A g<sup>−1</sup>. The hybrid battery also exhibits excellent catalytic stability. After 1000 cycles at a high current density of 15 A g<sup>−1</sup>, the capacity of the battery still remains 125.0 mAh, with a retention rate of approximately 90.9%. The improvement in battery performance is due to the use of NC to coat CeO<sub>2</sub>, which improves the limiting current and durability of the electrode. The presented hybrid proton batteries have further enriched the application of electrochemical energy storage devices, and the preliminary exploration of cathode catalysts significantly improved the catalytic performance of ORR under acidic conditions.</p><h3>Graphical Abstract</h3><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":536,"journal":{"name":"Electronic Materials Letters","volume":"20 6","pages":"807 - 817"},"PeriodicalIF":2.1,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141932532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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