Using first-principles calculations, we study the electronic and magnetic properties of monolayer PtS2 doped substitutionally with 3d transition metals. We obtain nonmagnetic semiconductors by doping with Ti and Ni, half-metals by doping with V and Cr, ferromagnetic semiconductors by doping with Co, and antiferromagnetic semiconductors by doping with Mn and Fe. Total magnetic moments of up to 3 μB are created. The Curie temperature is determined by means of a Heisenberg model in the mean-field approximation and adopting Monte Carlo simulations. 1T phase transition-metal dichal-cogenides turn out to be a promising platform for realizing two-dimensional magnetic semiconductors.
通过第一原理计算，我们研究了单层掺杂 3d 过渡金属的 PtS2 的电子和磁性能。通过掺杂 Ti 和 Ni，我们获得了非磁性半导体；通过掺杂 V 和 Cr，我们获得了半金属；通过掺杂 Co，我们获得了铁磁性半导体；通过掺杂 Mn 和 Fe，我们获得了反铁磁性半导体。产生的总磁矩可达 3 μB。居里温度是通过均场近似的海森堡模型和蒙特卡罗模拟确定的。1T 相过渡金属二卤化物被证明是实现二维磁性半导体的一个前景广阔的平台。
{"title":"Two-Dimensional Magnetic Semiconductors by Substitutional Doping of Monolayer PtS2","authors":"Zeyneb Bordjiba, Paresh C. Rout, Minglei Sun, Athmane Meddour, Udo Schwingenschlögl","doi":"10.1021/acsaelm.4c01196","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01196","url":null,"abstract":"Using first-principles calculations, we study the electronic and magnetic properties of monolayer PtS<sub>2</sub> doped substitutionally with 3d transition metals. We obtain nonmagnetic semiconductors by doping with Ti and Ni, half-metals by doping with V and Cr, ferromagnetic semiconductors by doping with Co, and antiferromagnetic semiconductors by doping with Mn and Fe. Total magnetic moments of up to 3 μ<sub>B</sub> are created. The Curie temperature is determined by means of a Heisenberg model in the mean-field approximation and adopting Monte Carlo simulations. 1T phase transition-metal dichal-cogenides turn out to be a promising platform for realizing two-dimensional magnetic semiconductors.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphene, with its high surface area, is an important sensing material but lacks selectivity. As tin oxide has a higher selectivity for ethanol, we fabricated a graphene field-effect transistor (GFET) sensor functionalized with tin nanoparticles (Sn NPs) to enhance its selectivity and sensitivity for ethanol detection. Among 200 nm, 500 nm, 1 μm, and 2 μm channel sizes, 1 nm thickness Sn NPs functionalized on 200 nm GFET sensors exhibited high sensitivity and selective detection of ethanol and ammonia among five tested gases in a real air environment. Moreover, they demonstrated high sensitivity for ethanol and ammonia, detecting concentrations as low as 100 ppb at room temperature. The postfabrication thermal annealing facilitates the formation of Sn NP clusters and voids within the smaller 200 nm graphene channel, contributing to the sensor’s high sensitivity. Furthermore, the catalytic reaction of ethanol and ammonia molecules with oxygen molecules in the presence of Sn NPs releases electrons, which are reflected in n-doping in the graphene sensor measurements. The potential of this highly sensitive and selective ethanol and ammonia detection of graphene sensors can be utilized with machine learning techniques in the sensor cluster to identify different gases.
{"title":"Room Temperature Real Air Highly Sensitive and Selective Detection of Ethanol and Ammonia Molecules Using Tin Nanoparticle-Functionalized Graphene Sensors","authors":"Manoharan Muruganathan, Md. Zahidul Islam, Afsal Kareekunnan, Yosuke Onda, Masashi Hattori, Hiroshi Mizuta","doi":"10.1021/acsaelm.4c01308","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01308","url":null,"abstract":"Graphene, with its high surface area, is an important sensing material but lacks selectivity. As tin oxide has a higher selectivity for ethanol, we fabricated a graphene field-effect transistor (GFET) sensor functionalized with tin nanoparticles (Sn NPs) to enhance its selectivity and sensitivity for ethanol detection. Among 200 nm, 500 nm, 1 μm, and 2 μm channel sizes, 1 nm thickness Sn NPs functionalized on 200 nm GFET sensors exhibited high sensitivity and selective detection of ethanol and ammonia among five tested gases in a real air environment. Moreover, they demonstrated high sensitivity for ethanol and ammonia, detecting concentrations as low as 100 ppb at room temperature. The postfabrication thermal annealing facilitates the formation of Sn NP clusters and voids within the smaller 200 nm graphene channel, contributing to the sensor’s high sensitivity. Furthermore, the catalytic reaction of ethanol and ammonia molecules with oxygen molecules in the presence of Sn NPs releases electrons, which are reflected in n-doping in the graphene sensor measurements. The potential of this highly sensitive and selective ethanol and ammonia detection of graphene sensors can be utilized with machine learning techniques in the sensor cluster to identify different gases.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The multinetwork hydrogel-based biomechanical sensor has attracted considerable attention due to its excellent mechanical properties. However, in most cases, due to the weak binding force of the hydrogel matrix to water and the uneven structure of the sensing layer, it is difficult to prepare pressure (strain) sensors that can quantify stimuli-response and be durable for long periods. Moreover, the preparation of hydrogels often involves the intervention and residue of toxic substances, making them unsuitable for monitoring biomechanical indicators. In this paper, we prepared a flexible, conductive biohydrogel capable of long-term storage using low-cost, biocompatible materials. The hydrogel is composed of lignosulfonate sodium and poly(vinyl alcohol), blended with acrylic acid and enhanced with various cations with different hydration abilities. The pressure sensor based on the as-prepared hydrogel exhibits a high sensitivity of 1.145 kPa–1 to medium pressure encountered by the human body (i.e., 0.1 to 10 kPa). Due to the high flexibility and toughness of the hydrogel, the corresponding pressure sensor demonstrates 2500 cycles of cycling stability. Also, the strain sensor based on the as-prepared hydrogel shows a wide testing range from 0 to 1100% and quantifies the strain–response physical process based on its mechanical and electrical properties, making it suitable for use. Due to the compressibility, high sensitivity, and long-term stability, the proposed sensors could show great potential in wearable electronic devices for monitoring biological activities.
{"title":"Green Durable Biomechanical Sensor Based on a Cation-Enhanced Hydrogel","authors":"YuXiang Qin, ZiCheng Zhou","doi":"10.1021/acsaelm.4c01218","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01218","url":null,"abstract":"The multinetwork hydrogel-based biomechanical sensor has attracted considerable attention due to its excellent mechanical properties. However, in most cases, due to the weak binding force of the hydrogel matrix to water and the uneven structure of the sensing layer, it is difficult to prepare pressure (strain) sensors that can quantify stimuli-response and be durable for long periods. Moreover, the preparation of hydrogels often involves the intervention and residue of toxic substances, making them unsuitable for monitoring biomechanical indicators. In this paper, we prepared a flexible, conductive biohydrogel capable of long-term storage using low-cost, biocompatible materials. The hydrogel is composed of lignosulfonate sodium and poly(vinyl alcohol), blended with acrylic acid and enhanced with various cations with different hydration abilities. The pressure sensor based on the as-prepared hydrogel exhibits a high sensitivity of 1.145 kPa<sup>–1</sup> to medium pressure encountered by the human body (i.e., 0.1 to 10 kPa). Due to the high flexibility and toughness of the hydrogel, the corresponding pressure sensor demonstrates 2500 cycles of cycling stability. Also, the strain sensor based on the as-prepared hydrogel shows a wide testing range from 0 to 1100% and quantifies the strain–response physical process based on its mechanical and electrical properties, making it suitable for use. Due to the compressibility, high sensitivity, and long-term stability, the proposed sensors could show great potential in wearable electronic devices for monitoring biological activities.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andrew R. Balog, Channyung Lee, Daniel Duarte-Ruiz, Sai Venkata Gayathri Ayyagari, Jani Jesenovec, Adrian E. Chmielewski, Leixin Miao, Benjamin L. Dutton, John McCloy, Caterina Cocchi, Elif Ertekin, Nasim Alem
β-Ga2O3 is a promising ultrawide bandgap semiconductor for next-generation power electronics, but the unintended formation of γ-Ga2O3 in β-Ga2O3 crystals has been observed in a variety of situations. Such defective inclusions, resulting from growth kinetics or ion-induced damage, can degrade the material performance and alter the local electronic structure. Previous studies have only examined the presence of γ-Ga2O3 in β-Ga2O3 thin-film structures. In this work, we observe the ubiquitous formation of a thin γ-Ga2O3 layer on the surface of mechanically exfoliated melt grown Al- and Sc-alloyed β-Ga2O3 single crystals and characterize the atomic scale structure across the interface using scanning transmission electron microscopy. Direct imaging paired with electron diffraction confirms γ-Ga2O3 formation, and orientation relationships are determined across the interface. Electron energy loss spectroscopy identifies the O K-edge spectral fingerprint of γ-Ga2O3, while many-body perturbation theory on top of density functional theory explains the shift of the spectral intensity between β- and γ-Ga2O3 as an interplay of excitonic and electronic effects. Further first-principles studies evaluate the role of strain on phase stability and identify that at an 8.5% tensile strain, γ-Ga2O3 becomes energetically favored over β-Ga2O3. Stabilization of the β phase of Ga2O3 under compressive stress is further confirmed through electron diffraction studies of the regions surrounding Vickers indentations. Phase stability is also observed to be independent of the alloying element. These findings confirm the capability for γ-Ga2O3 to occur under extreme environments while also providing evidence that strain is the underlying driving force causing the phase transformation.
{"title":"Determination of the β to γ Phase Transformation Mechanism in Sc- and Al-Alloyed β-Ga2O3 Crystals","authors":"Andrew R. Balog, Channyung Lee, Daniel Duarte-Ruiz, Sai Venkata Gayathri Ayyagari, Jani Jesenovec, Adrian E. Chmielewski, Leixin Miao, Benjamin L. Dutton, John McCloy, Caterina Cocchi, Elif Ertekin, Nasim Alem","doi":"10.1021/acsaelm.4c00762","DOIUrl":"https://doi.org/10.1021/acsaelm.4c00762","url":null,"abstract":"β-Ga<sub>2</sub>O<sub>3</sub> is a promising ultrawide bandgap semiconductor for next-generation power electronics, but the unintended formation of γ-Ga<sub>2</sub>O<sub>3</sub> in β-Ga<sub>2</sub>O<sub>3</sub> crystals has been observed in a variety of situations. Such defective inclusions, resulting from growth kinetics or ion-induced damage, can degrade the material performance and alter the local electronic structure. Previous studies have only examined the presence of γ-Ga<sub>2</sub>O<sub>3</sub> in β-Ga<sub>2</sub>O<sub>3</sub> thin-film structures. In this work, we observe the ubiquitous formation of a thin γ-Ga<sub>2</sub>O<sub>3</sub> layer on the surface of mechanically exfoliated melt grown Al- and Sc-alloyed β-Ga<sub>2</sub>O<sub>3</sub> single crystals and characterize the atomic scale structure across the interface using scanning transmission electron microscopy. Direct imaging paired with electron diffraction confirms γ-Ga<sub>2</sub>O<sub>3</sub> formation, and orientation relationships are determined across the interface. Electron energy loss spectroscopy identifies the O K-edge spectral fingerprint of γ-Ga<sub>2</sub>O<sub>3</sub>, while many-body perturbation theory on top of density functional theory explains the shift of the spectral intensity between β- and γ-Ga<sub>2</sub>O<sub>3</sub> as an interplay of excitonic and electronic effects. Further first-principles studies evaluate the role of strain on phase stability and identify that at an 8.5% tensile strain, γ-Ga<sub>2</sub>O<sub>3</sub> becomes energetically favored over β-Ga<sub>2</sub>O<sub>3</sub>. Stabilization of the β phase of Ga<sub>2</sub>O<sub>3</sub> under compressive stress is further confirmed through electron diffraction studies of the regions surrounding Vickers indentations. Phase stability is also observed to be independent of the alloying element. These findings confirm the capability for γ-Ga<sub>2</sub>O<sub>3</sub> to occur under extreme environments while also providing evidence that strain is the underlying driving force causing the phase transformation.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Quynh Trang Tran, Thi Bich Tuyen Huynh, Tu Huynh Pham, Umeshwar Reddy Nallasani, Hong-Jyun Wang, Nhu Quynh Diep, Wu-Ching Chou, Van-Qui Le, Kung-Hwa Wei, Thanh Tra Vu
Molecular beam epitaxy (MBE) of InGaSe/2D-GaSe/sapphire hybrid structures has been reported in this study. We explore that MBE of the InGaSe layer on 2D-GaSe/sapphire results in a mixed dimensional alloy, comprising two-dimensional (2D) hexagonal-InxGa1–xSe and three-dimensional (3D) zinc blende (InGa)2Se3, in which the 3D one is more favorable. It is also revealed that the surface morphology of the underneath 2D-GaSe layer grown under different modes, i.e., screw-dislocation-driven (SDD-GaSe) and layer-by-layer (LBL-GaSe), significantly governs the epitaxial behavior of the InGaSe top layer. Indeed, in the case of the InGaSe alloy grown on 2D LBL-GaSe, it is more and more preferable to nucleate from the edges of GaSe triangular flakes with increasing deposition temperature, thus promoting lateral growth. On the other hand, the surface morphology of InGaSe alloy on 2D SDD-GaSe appears to have a high density of nanoclusters. Moreover, a structural transition from 2D-to-3D has been recognized from in-situ RHEED observation, in which its on-set point is likely accelerated at lower growth temperatures. The gain from this study benefits our understanding of the mixed dimensional GaSe-based heterostructures by MBE, in terms of exploring semiconductor physics and widening potential applications of group-III metal chalcogenides.
{"title":"Molecular Beam Epitaxy of Mixed Dimensional InGaSe/GaSe Hybrid Heterostructures on C-Sapphire","authors":"Quynh Trang Tran, Thi Bich Tuyen Huynh, Tu Huynh Pham, Umeshwar Reddy Nallasani, Hong-Jyun Wang, Nhu Quynh Diep, Wu-Ching Chou, Van-Qui Le, Kung-Hwa Wei, Thanh Tra Vu","doi":"10.1021/acsaelm.4c01325","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01325","url":null,"abstract":"Molecular beam epitaxy (MBE) of InGaSe/2D-GaSe/sapphire hybrid structures has been reported in this study. We explore that MBE of the InGaSe layer on 2D-GaSe/sapphire results in a mixed dimensional alloy, comprising two-dimensional (2D) hexagonal-In<sub><i>x</i></sub>Ga<sub>1–<i>x</i></sub>Se and three-dimensional (3D) zinc blende (InGa)<sub>2</sub>Se<sub>3</sub>, in which the 3D one is more favorable. It is also revealed that the surface morphology of the underneath 2D-GaSe layer grown under different modes, i.e., screw-dislocation-driven (SDD-GaSe) and layer-by-layer (LBL-GaSe), significantly governs the epitaxial behavior of the InGaSe top layer. Indeed, in the case of the InGaSe alloy grown on 2D LBL-GaSe, it is more and more preferable to nucleate from the edges of GaSe triangular flakes with increasing deposition temperature, thus promoting lateral growth. On the other hand, the surface morphology of InGaSe alloy on 2D SDD-GaSe appears to have a high density of nanoclusters. Moreover, a structural transition from 2D-to-3D has been recognized from in-situ RHEED observation, in which its on-set point is likely accelerated at lower growth temperatures. The gain from this study benefits our understanding of the mixed dimensional GaSe-based heterostructures by MBE, in terms of exploring semiconductor physics and widening potential applications of group-III metal chalcogenides.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Toward advancing energy sustainability, collecting low-frequency mechanical vibration energy from the environment has become an important research area. This paper introduces the design and implementation of a noncontact pendulum-structured hybrid triboelectric–electromagnetic nanogenerator (NCP-HNG) for monitoring low-frequency vibrations, continuously collecting low-frequency mechanical energy, and converting this energy into electricity. Design of the pendulum structure allows the generator to efficiently capture vibrations under low-frequency conditions, thus improving energy conversion efficiency and enabling more effective environmental energy harvesting. Through optimized design and energy management circuits, the NCP-HNG exhibits efficient charging, continuously collecting energy from low-frequency vibration environments and showing charging of a 100 mAh lithium battery to 3.30 V in just 12 min. The use of noncontact mode significantly reduces material wear, providing the device with a longer life span. Consequently, it offers a reliable self-powered energy solution for wireless sensor networks, health monitoring devices, and infrastructure health monitoring, among other fields.
为推进能源的可持续发展，从环境中收集低频机械振动能量已成为一个重要的研究领域。本文介绍了一种非接触摆式结构混合三电电磁纳米发电机（NCP-HNG）的设计与实现，该发电机用于监测低频振动，持续收集低频机械能，并将这些能量转化为电能。摆锤结构的设计使发电机能够有效捕捉低频条件下的振动，从而提高能量转换效率，实现更有效的环境能量收集。通过优化设计和能量管理电路，NCP-HNG 实现了高效充电，可持续从低频振动环境中收集能量，仅需 12 分钟即可将 100 mAh 锂电池充电至 3.30 V。非接触模式的使用大大减少了材料磨损，延长了设备的使用寿命。因此，它为无线传感器网络、健康监测设备和基础设施健康监测等领域提供了可靠的自供电能源解决方案。
{"title":"Hybrid Triboelectric–Electromagnetic Nanogenerator Based on a Noncontact Pendulum Structure for Low-Frequency Vibration Monitoring and Energy Harvesting","authors":"Xiangming Gao, Mingkun Huang, Yongju Wang, Shijie Zhang","doi":"10.1021/acsaelm.4c01226","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01226","url":null,"abstract":"Toward advancing energy sustainability, collecting low-frequency mechanical vibration energy from the environment has become an important research area. This paper introduces the design and implementation of a noncontact pendulum-structured hybrid triboelectric–electromagnetic nanogenerator (NCP-HNG) for monitoring low-frequency vibrations, continuously collecting low-frequency mechanical energy, and converting this energy into electricity. Design of the pendulum structure allows the generator to efficiently capture vibrations under low-frequency conditions, thus improving energy conversion efficiency and enabling more effective environmental energy harvesting. Through optimized design and energy management circuits, the NCP-HNG exhibits efficient charging, continuously collecting energy from low-frequency vibration environments and showing charging of a 100 mAh lithium battery to 3.30 V in just 12 min. The use of noncontact mode significantly reduces material wear, providing the device with a longer life span. Consequently, it offers a reliable self-powered energy solution for wireless sensor networks, health monitoring devices, and infrastructure health monitoring, among other fields.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study introduces a highly flexible, vertically installed electrospun PVDF/CoFe2O4 composite-based Magneto-Mechano-Electric (MME) generator designed to capture and utilize environmental stray magnetic noise, a prevalent form of waste energy from electrical power transmission systems. We fabricated highly flexible, freestanding magnetoelectric composite electrospun fibers by combining piezoelectric PVDF polymer and magnetostrictive CoFe2O4. XRD and FTIR analyses confirmed a significant enhancement in the ferroelectric β-phase content, reaching 86% with the incorporation of CoFe2O4. The electrostatic interaction mechanism between PVDF and CoFe2O4 was explained and validated through Zeta potential and XPS analyses. The developed MME generator demonstrated a high output voltage and power density of 12.1 V and 174 μW/m2, respectively, under a low AC magnetic field of 6 Oe. The detailed mechanism of energy generation in the MME device has been explained. The fabricated MME device also demonstrated the highest magnetoelectric voltage coefficient (αMME) value of 224 V cm–1 Oe–1, even in the absence of a magnetic bias DC field. The MME generator has demonstrated stable output harvesting performance across 50,000 testing cycles. This MME generator efficiently harvested low and weak parasitic magnetic noise from various electrical appliances, such as dryers, kettles, and iron boxes, thereby enabling a remote power supply to consumer electronics.
{"title":"Enhancing Stray Magnetic Energy Harvesting with Flexible PVDF/CoFe2O4 Electrospun Fiber Composite Magneto-Mechano-Electric Generators","authors":"Durga Prasad Pabba, Nayak Ram, J. Kaarthik, Naveen Kumar Pabba, Annapureddy Venkateswarlu","doi":"10.1021/acsaelm.4c01173","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01173","url":null,"abstract":"This study introduces a highly flexible, vertically installed electrospun PVDF/CoFe<sub>2</sub>O<sub>4</sub> composite-based Magneto-Mechano-Electric (MME) generator designed to capture and utilize environmental stray magnetic noise, a prevalent form of waste energy from electrical power transmission systems. We fabricated highly flexible, freestanding magnetoelectric composite electrospun fibers by combining piezoelectric PVDF polymer and magnetostrictive CoFe<sub>2</sub>O<sub>4</sub>. XRD and FTIR analyses confirmed a significant enhancement in the ferroelectric β-phase content, reaching 86% with the incorporation of CoFe<sub>2</sub>O<sub>4</sub>. The electrostatic interaction mechanism between PVDF and CoFe<sub>2</sub>O<sub>4</sub> was explained and validated through Zeta potential and XPS analyses. The developed MME generator demonstrated a high output voltage and power density of 12.1 V and 174 μW/m<sup>2</sup>, respectively, under a low AC magnetic field of 6 Oe. The detailed mechanism of energy generation in the MME device has been explained. The fabricated MME device also demonstrated the highest magnetoelectric voltage coefficient (α<sub>MME</sub>) value of 224 V cm<sup>–1</sup> Oe<sup>–1</sup>, even in the absence of a magnetic bias DC field. The MME generator has demonstrated stable output harvesting performance across 50,000 testing cycles. This MME generator efficiently harvested low and weak parasitic magnetic noise from various electrical appliances, such as dryers, kettles, and iron boxes, thereby enabling a remote power supply to consumer electronics.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Surajit Sardar, Rimjhim Yadav, Jai Dev, Surinder P. Singh, Pallavi Kushwaha
Supercapacitors have emerged as promising energy storage devices due to their high power density, rapid charging/discharging rates, and long cycle life. Ruthenium dioxide (RuO2) is a promising material for supercapacitor electrodes due to its excellent electrical conductivity and pseudocapacitive behavior. Here, we synthesize Ru1–xPdxO2 (x = 0, 0.05, 0.10, and 0.17) by a solid-state route, expecting to alter the electronic structure and specific capacitance with Pd doping. The X-ray diffraction (XRD) analysis suggests that all prepared samples are formed in the desired composition, showing that the crystallite size increases successively with increasing Pd concentration. Cyclic voltammetry (CV) measurements demonstrate that the systematic substitution of 17% Pd in RuO2 contributes to enhancing specific capacitance by ∼15 times (∼1163 F/g) in comparison to parent RuO2 (∼79 F/g), indicating its superior charge storage ability. Further, the decay in specific capacitance with increasing scan rate is only 5% (x = 0.17) in comparison to undoped RuO2, indicating the higher stability of the electrode. The CV of Ru1–xPdxO2 (x = 0.17) exhibits both Faradaic and capacitive electrochemical processes at the electrode/electrolyte interface, suggesting hybrid battery–supercapacitor characteristics. Ru1–xPdxO2 (x = 0.17) represents a promising electrode material for hybrid battery–supercapacitors, offering synergistic enhancements in specific capacitance and stability.
{"title":"Pd-Doped RuO2: A Promising Electrode Material with Battery–Supercapacitor Hybrid Characteristics","authors":"Surajit Sardar, Rimjhim Yadav, Jai Dev, Surinder P. Singh, Pallavi Kushwaha","doi":"10.1021/acsaelm.4c01014","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01014","url":null,"abstract":"Supercapacitors have emerged as promising energy storage devices due to their high power density, rapid charging/discharging rates, and long cycle life. Ruthenium dioxide (RuO<sub>2</sub>) is a promising material for supercapacitor electrodes due to its excellent electrical conductivity and pseudocapacitive behavior. Here, we synthesize Ru<sub>1–<i>x</i></sub>Pd<sub><i>x</i></sub>O<sub>2</sub> (<i>x</i> = 0, 0.05, 0.10, and 0.17) by a solid-state route, expecting to alter the electronic structure and specific capacitance with Pd doping. The X-ray diffraction (XRD) analysis suggests that all prepared samples are formed in the desired composition, showing that the crystallite size increases successively with increasing Pd concentration. Cyclic voltammetry (CV) measurements demonstrate that the systematic substitution of 17% Pd in RuO<sub>2</sub> contributes to enhancing specific capacitance by ∼15 times (∼1163 F/g) in comparison to parent RuO<sub>2</sub> (∼79 F/g), indicating its superior charge storage ability. Further, the decay in specific capacitance with increasing scan rate is only 5% (<i>x</i> = 0.17) in comparison to undoped RuO<sub>2</sub>, indicating the higher stability of the electrode. The CV of Ru<sub>1–<i>x</i></sub>Pd<sub><i>x</i></sub>O<sub>2</sub> (<i>x</i> = 0.17) exhibits both Faradaic and capacitive electrochemical processes at the electrode/electrolyte interface, suggesting hybrid battery–supercapacitor characteristics. Ru<sub>1–<i>x</i></sub>Pd<sub><i>x</i></sub>O<sub>2</sub> (<i>x</i> = 0.17) represents a promising electrode material for hybrid battery–supercapacitors, offering synergistic enhancements in specific capacitance and stability.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142260864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hudson A. Bicalho, Lavinia A. Trifoi, Victor Quezada-Novoa, Ashlee J. Howarth
The design and synthesis of luminescent and photoactive metal–organic frameworks (MOFs) are of interest from both a fundamental and application standpoint. Luminescent and photoactive MOFs can be designed to have photophysical properties similar to those of other materials, with the added benefit of possessing a large surface area and high porosity. The incorporation of lanthanoids within cluster-based MOF metal nodes coupled with the strategic utilization of conjugated organic linkers allows for the design of materials with unique and highly tunable photophysical and photochemical properties. This Spotlight on Applications highlights our efforts in the development of various luminescent and photochemically active rare-earth (RE) cluster-based MOFs as well as the potential applications of these materials. The interplay between lanthanoid elements and organic linkers in MOFs is crucial toward the design and synthesis of RE-MOFs with tailored photophysical and photochemical properties. The paper focuses on methods for tuning the luminescent properties of RE-MOFs via the antenna effect, resulting in either metal-based, linker-based, or dual metal- and linker-based luminescence. Furthermore, strategies for producing singlet oxygen by the incorporation of photosensitizers in RE-MOFs are discussed. Through this work, we aim to shine light on the diversity of the structure, function, and potential applications of RE-MOFs.
{"title":"Tuning the Photophysical and Photochemical Properties of Rare-Earth Cluster-Based Metal–Organic Frameworks","authors":"Hudson A. Bicalho, Lavinia A. Trifoi, Victor Quezada-Novoa, Ashlee J. Howarth","doi":"10.1021/acsaelm.4c01188","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01188","url":null,"abstract":"The design and synthesis of luminescent and photoactive metal–organic frameworks (MOFs) are of interest from both a fundamental and application standpoint. Luminescent and photoactive MOFs can be designed to have photophysical properties similar to those of other materials, with the added benefit of possessing a large surface area and high porosity. The incorporation of lanthanoids within cluster-based MOF metal nodes coupled with the strategic utilization of conjugated organic linkers allows for the design of materials with unique and highly tunable photophysical and photochemical properties. This Spotlight on Applications highlights our efforts in the development of various luminescent and photochemically active rare-earth (RE) cluster-based MOFs as well as the potential applications of these materials. The interplay between lanthanoid elements and organic linkers in MOFs is crucial toward the design and synthesis of RE-MOFs with tailored photophysical and photochemical properties. The paper focuses on methods for tuning the luminescent properties of RE-MOFs via the antenna effect, resulting in either metal-based, linker-based, or dual metal- and linker-based luminescence. Furthermore, strategies for producing singlet oxygen by the incorporation of photosensitizers in RE-MOFs are discussed. Through this work, we aim to shine light on the diversity of the structure, function, and potential applications of RE-MOFs.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In terms of practical applications, a performance bottleneck with spin-transfer-torque magnetic random-access memory (STT-MRAM) devices is evident at varying temperatures, notably with respect to data retention at warm temperatures and endurance under cold conditions. Effective strategies to enhance the STT efficiency should be targeted at broadening the applicable temperature range. In this study, multi-interface structured and optimized materials have been incorporated in the magnetic tunnel junction (MTJ) free layer to augment perpendicular magnetic anisotropy (PMA) and mitigate temperature dependence. The thermal stability factor of the MRAM test chip exceeded 40 at 260 °C, which is sufficiently high for 5× solder reflow. Moreover, the endurance was retained for 2 × 107 cycles at room temperature. The enhanced PMA is effective in augmenting the read margin (TMR/Rp_CV), surpassing 30, a value that exceeds the typical sense amplifier (SA) requirement. These findings demonstrate significant potential for multi-interface MTJ and can serve as the basis for establishing an evaluation system for future spintronic chips.
{"title":"Temperature Dependence Strategy for Achieving Enhanced Reflow-Capable MRAM with a Multi-Interface Structure","authors":"Yihui Sun, Fantao Meng, Yaohua Wang","doi":"10.1021/acsaelm.4c01337","DOIUrl":"https://doi.org/10.1021/acsaelm.4c01337","url":null,"abstract":"In terms of practical applications, a performance bottleneck with spin-transfer-torque magnetic random-access memory (STT-MRAM) devices is evident at varying temperatures, notably with respect to data retention at warm temperatures and endurance under cold conditions. Effective strategies to enhance the STT efficiency should be targeted at broadening the applicable temperature range. In this study, multi-interface structured and optimized materials have been incorporated in the magnetic tunnel junction (MTJ) free layer to augment perpendicular magnetic anisotropy (PMA) and mitigate temperature dependence. The thermal stability factor of the MRAM test chip exceeded 40 at 260 °C, which is sufficiently high for 5× solder reflow. Moreover, the endurance was retained for 2 × 10<sup>7</sup> cycles at room temperature. The enhanced PMA is effective in augmenting the read margin (TMR/Rp_CV), surpassing 30, a value that exceeds the typical sense amplifier (SA) requirement. These findings demonstrate significant potential for multi-interface MTJ and can serve as the basis for establishing an evaluation system for future spintronic chips.","PeriodicalId":3,"journal":{"name":"ACS Applied Electronic Materials","volume":null,"pages":null},"PeriodicalIF":4.7,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142261082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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